From 5d053f36d6b26f8d68cc8e9b718e317491cf6d77 Mon Sep 17 00:00:00 2001
From: Thomas Braun <thomas.braun@byte-physics.de>
Date: Sun, 30 Aug 2020 20:31:39 +0200
Subject: [PATCH 1/7] Tests: Fix warning about unused result

GCC 7.0 and higher complain when compiled in release mode about the
unused result of parse-like functions. This makes totally sense as these
are marked with JSON_HEDLEY_WARN_UNUSED_RESULT.

Store the result in a json object named _ to silence that warning.
---
 test/src/unit-bson.cpp            |  5 ++-
 test/src/unit-cbor.cpp            | 64 ++++++++++++++++++-------------
 test/src/unit-class_parser.cpp    |  5 ++-
 test/src/unit-deserialization.cpp | 48 +++++++++++++++--------
 test/src/unit-ubjson.cpp          |  7 ++--
 test/src/unit-unicode.cpp         |  3 +-
 6 files changed, 82 insertions(+), 50 deletions(-)

diff --git a/test/src/unit-bson.cpp b/test/src/unit-bson.cpp
index 6b2e76dad08..3be72c7d479 100644
--- a/test/src/unit-bson.cpp
+++ b/test/src/unit-bson.cpp
@@ -867,8 +867,9 @@ TEST_CASE("Negative size of binary value")
 
         0x00 // end marker
     };
-    CHECK_THROWS_AS(json::from_bson(input), json::parse_error);
-    CHECK_THROWS_WITH(json::from_bson(input), "[json.exception.parse_error.112] parse error at byte 15: syntax error while parsing BSON binary: byte array length cannot be negative, is -1");
+    json _;
+    CHECK_THROWS_AS(_ = json::from_bson(input), json::parse_error);
+    CHECK_THROWS_WITH(_ = json::from_bson(input), "[json.exception.parse_error.112] parse error at byte 15: syntax error while parsing BSON binary: byte array length cannot be negative, is -1");
 }
 
 TEST_CASE("Unsupported BSON input")
diff --git a/test/src/unit-cbor.cpp b/test/src/unit-cbor.cpp
index ca4b781a12f..9ed80c8f1a9 100644
--- a/test/src/unit-cbor.cpp
+++ b/test/src/unit-cbor.cpp
@@ -1591,14 +1591,16 @@ TEST_CASE("CBOR")
             {
                 // array with three empty byte strings
                 std::vector<std::uint8_t> input = {0x83, 0x40, 0x40, 0x40};
-                CHECK_NOTHROW(json::from_cbor(input));
+                json _;
+                CHECK_NOTHROW(_ = json::from_cbor(input));
             }
 
             SECTION("binary in object")
             {
                 // object mapping "foo" to empty byte string
                 std::vector<std::uint8_t> input = {0xA1, 0x63, 0x66, 0x6F, 0x6F, 0x40};
-                CHECK_NOTHROW(json::from_cbor(input));
+                json _;
+                CHECK_NOTHROW(_ = json::from_cbor(input));
             }
 
             SECTION("SAX callback with binary")
@@ -2551,8 +2553,9 @@ TEST_CASE("Tagged values")
             v_tagged.insert(v_tagged.begin(), b);
 
             // check that parsing fails in error mode
-            CHECK_THROWS_AS(json::from_cbor(v_tagged), json::parse_error);
-            CHECK_THROWS_AS(json::from_cbor(v_tagged, true, true, json::cbor_tag_handler_t::error), json::parse_error);
+            json _;
+            CHECK_THROWS_AS(_ = json::from_cbor(v_tagged), json::parse_error);
+            CHECK_THROWS_AS(_ = json::from_cbor(v_tagged, true, true, json::cbor_tag_handler_t::error), json::parse_error);
 
             // check that parsing succeeds and gets original value in ignore mode
             auto j_tagged = json::from_cbor(v_tagged, true, true, json::cbor_tag_handler_t::ignore);
@@ -2570,8 +2573,9 @@ TEST_CASE("Tagged values")
             v_tagged.insert(v_tagged.begin(), 0xD8); // tag
 
             // check that parsing fails in error mode
-            CHECK_THROWS_AS(json::from_cbor(v_tagged), json::parse_error);
-            CHECK_THROWS_AS(json::from_cbor(v_tagged, true, true, json::cbor_tag_handler_t::error), json::parse_error);
+            json _;
+            CHECK_THROWS_AS(_ = json::from_cbor(v_tagged), json::parse_error);
+            CHECK_THROWS_AS(_ = json::from_cbor(v_tagged, true, true, json::cbor_tag_handler_t::error), json::parse_error);
 
             // check that parsing succeeds and gets original value in ignore mode
             auto j_tagged = json::from_cbor(v_tagged, true, true, json::cbor_tag_handler_t::ignore);
@@ -2585,9 +2589,10 @@ TEST_CASE("Tagged values")
             v_tagged.insert(v_tagged.begin(), 0xD8); // tag
 
             // check that parsing fails in all modes
-            CHECK_THROWS_AS(json::from_cbor(v_tagged), json::parse_error);
-            CHECK_THROWS_AS(json::from_cbor(v_tagged, true, true, json::cbor_tag_handler_t::error), json::parse_error);
-            CHECK_THROWS_AS(json::from_cbor(v_tagged, true, true, json::cbor_tag_handler_t::ignore), json::parse_error);
+            json _;
+            CHECK_THROWS_AS(_ = json::from_cbor(v_tagged), json::parse_error);
+            CHECK_THROWS_AS(_ = json::from_cbor(v_tagged, true, true, json::cbor_tag_handler_t::error), json::parse_error);
+            CHECK_THROWS_AS(_ = json::from_cbor(v_tagged, true, true, json::cbor_tag_handler_t::ignore), json::parse_error);
         }
     }
 
@@ -2602,8 +2607,9 @@ TEST_CASE("Tagged values")
             v_tagged.insert(v_tagged.begin(), 0xD9); // tag
 
             // check that parsing fails in error mode
-            CHECK_THROWS_AS(json::from_cbor(v_tagged), json::parse_error);
-            CHECK_THROWS_AS(json::from_cbor(v_tagged, true, true, json::cbor_tag_handler_t::error), json::parse_error);
+            json _;
+            CHECK_THROWS_AS(_ = json::from_cbor(v_tagged), json::parse_error);
+            CHECK_THROWS_AS(_ = json::from_cbor(v_tagged, true, true, json::cbor_tag_handler_t::error), json::parse_error);
 
             // check that parsing succeeds and gets original value in ignore mode
             auto j_tagged = json::from_cbor(v_tagged, true, true, json::cbor_tag_handler_t::ignore);
@@ -2618,9 +2624,10 @@ TEST_CASE("Tagged values")
             v_tagged.insert(v_tagged.begin(), 0xD9); // tag
 
             // check that parsing fails in all modes
-            CHECK_THROWS_AS(json::from_cbor(v_tagged), json::parse_error);
-            CHECK_THROWS_AS(json::from_cbor(v_tagged, true, true, json::cbor_tag_handler_t::error), json::parse_error);
-            CHECK_THROWS_AS(json::from_cbor(v_tagged, true, true, json::cbor_tag_handler_t::ignore), json::parse_error);
+            json _;
+            CHECK_THROWS_AS(_ = json::from_cbor(v_tagged), json::parse_error);
+            CHECK_THROWS_AS(_ = json::from_cbor(v_tagged, true, true, json::cbor_tag_handler_t::error), json::parse_error);
+            CHECK_THROWS_AS(_ = json::from_cbor(v_tagged, true, true, json::cbor_tag_handler_t::ignore), json::parse_error);
         }
     }
 
@@ -2637,8 +2644,9 @@ TEST_CASE("Tagged values")
             v_tagged.insert(v_tagged.begin(), 0xDA); // tag
 
             // check that parsing fails in error mode
-            CHECK_THROWS_AS(json::from_cbor(v_tagged), json::parse_error);
-            CHECK_THROWS_AS(json::from_cbor(v_tagged, true, true, json::cbor_tag_handler_t::error), json::parse_error);
+            json _;
+            CHECK_THROWS_AS(_ = json::from_cbor(v_tagged), json::parse_error);
+            CHECK_THROWS_AS(_ = json::from_cbor(v_tagged, true, true, json::cbor_tag_handler_t::error), json::parse_error);
 
             // check that parsing succeeds and gets original value in ignore mode
             auto j_tagged = json::from_cbor(v_tagged, true, true, json::cbor_tag_handler_t::ignore);
@@ -2655,9 +2663,10 @@ TEST_CASE("Tagged values")
             v_tagged.insert(v_tagged.begin(), 0xDA); // tag
 
             // check that parsing fails in all modes
-            CHECK_THROWS_AS(json::from_cbor(v_tagged), json::parse_error);
-            CHECK_THROWS_AS(json::from_cbor(v_tagged, true, true, json::cbor_tag_handler_t::error), json::parse_error);
-            CHECK_THROWS_AS(json::from_cbor(v_tagged, true, true, json::cbor_tag_handler_t::ignore), json::parse_error);
+            json _;
+            CHECK_THROWS_AS(_ = json::from_cbor(v_tagged), json::parse_error);
+            CHECK_THROWS_AS(_ = json::from_cbor(v_tagged, true, true, json::cbor_tag_handler_t::error), json::parse_error);
+            CHECK_THROWS_AS(_ = json::from_cbor(v_tagged, true, true, json::cbor_tag_handler_t::ignore), json::parse_error);
         }
     }
 
@@ -2678,8 +2687,9 @@ TEST_CASE("Tagged values")
             v_tagged.insert(v_tagged.begin(), 0xDB); // tag
 
             // check that parsing fails in error mode
-            CHECK_THROWS_AS(json::from_cbor(v_tagged), json::parse_error);
-            CHECK_THROWS_AS(json::from_cbor(v_tagged, true, true, json::cbor_tag_handler_t::error), json::parse_error);
+            json _;
+            CHECK_THROWS_AS(_ = json::from_cbor(v_tagged), json::parse_error);
+            CHECK_THROWS_AS(_ = json::from_cbor(v_tagged, true, true, json::cbor_tag_handler_t::error), json::parse_error);
 
             // check that parsing succeeds and gets original value in ignore mode
             auto j_tagged = json::from_cbor(v_tagged, true, true, json::cbor_tag_handler_t::ignore);
@@ -2700,9 +2710,10 @@ TEST_CASE("Tagged values")
             v_tagged.insert(v_tagged.begin(), 0xDB); // tag
 
             // check that parsing fails in all modes
-            CHECK_THROWS_AS(json::from_cbor(v_tagged), json::parse_error);
-            CHECK_THROWS_AS(json::from_cbor(v_tagged, true, true, json::cbor_tag_handler_t::error), json::parse_error);
-            CHECK_THROWS_AS(json::from_cbor(v_tagged, true, true, json::cbor_tag_handler_t::ignore), json::parse_error);
+            json _;
+            CHECK_THROWS_AS(_ = json::from_cbor(v_tagged), json::parse_error);
+            CHECK_THROWS_AS(_ = json::from_cbor(v_tagged, true, true, json::cbor_tag_handler_t::error), json::parse_error);
+            CHECK_THROWS_AS(_ = json::from_cbor(v_tagged, true, true, json::cbor_tag_handler_t::ignore), json::parse_error);
         }
     }
 
@@ -2717,8 +2728,9 @@ TEST_CASE("Tagged values")
         CHECK(vec == std::vector<std::uint8_t> {0xA1, 0x66, 0x62, 0x69, 0x6E, 0x61, 0x72, 0x79, 0xD8, 0x2A, 0x44, 0xCA, 0xFE, 0xBA, 0xBE});
 
         // parse error when parsing tagged value
-        CHECK_THROWS_AS(json::from_cbor(vec), json::parse_error);
-        CHECK_THROWS_WITH(json::from_cbor(vec), "[json.exception.parse_error.112] parse error at byte 9: syntax error while parsing CBOR value: invalid byte: 0xD8");
+        json _;
+        CHECK_THROWS_AS(_ = json::from_cbor(vec), json::parse_error);
+        CHECK_THROWS_WITH(_ = json::from_cbor(vec), "[json.exception.parse_error.112] parse error at byte 9: syntax error while parsing CBOR value: invalid byte: 0xD8");
 
         // binary without subtype when tags are ignored
         json jb = json::from_cbor(vec, true, true, json::cbor_tag_handler_t::ignore);
diff --git a/test/src/unit-class_parser.cpp b/test/src/unit-class_parser.cpp
index 0cffee02ae3..d0335c94847 100644
--- a/test/src/unit-class_parser.cpp
+++ b/test/src/unit-class_parser.cpp
@@ -1879,7 +1879,8 @@ TEST_CASE("parser class")
 
     SECTION("error messages for comments")
     {
-        CHECK_THROWS_WITH_AS(json::parse("/a", nullptr, true, true), "[json.exception.parse_error.101] parse error at line 1, column 2: syntax error while parsing value - invalid comment; expecting '/' or '*' after '/'; last read: '/a'", json::parse_error);
-        CHECK_THROWS_WITH_AS(json::parse("/*", nullptr, true, true), "[json.exception.parse_error.101] parse error at line 1, column 3: syntax error while parsing value - invalid comment; missing closing '*/'; last read: '/*<U+0000>'", json::parse_error);
+        json _;
+        CHECK_THROWS_WITH_AS(_ = json::parse("/a", nullptr, true, true), "[json.exception.parse_error.101] parse error at line 1, column 2: syntax error while parsing value - invalid comment; expecting '/' or '*' after '/'; last read: '/a'", json::parse_error);
+        CHECK_THROWS_WITH_AS(_ = json::parse("/*", nullptr, true, true), "[json.exception.parse_error.101] parse error at line 1, column 3: syntax error while parsing value - invalid comment; missing closing '*/'; last read: '/*<U+0000>'", json::parse_error);
     }
 }
diff --git a/test/src/unit-deserialization.cpp b/test/src/unit-deserialization.cpp
index 716564c0a44..d2db7e80c3d 100644
--- a/test/src/unit-deserialization.cpp
+++ b/test/src/unit-deserialization.cpp
@@ -537,7 +537,8 @@ TEST_CASE("deserialization")
             SECTION("with empty range")
             {
                 std::vector<uint8_t> v;
-                CHECK_THROWS_AS(json::parse(std::begin(v), std::end(v)), json::parse_error&);
+                json _;
+                CHECK_THROWS_AS(_ = json::parse(std::begin(v), std::end(v)), json::parse_error&);
                 CHECK(!json::accept(std::begin(v), std::end(v)));
 
                 SaxEventLogger l;
@@ -553,7 +554,8 @@ TEST_CASE("deserialization")
             SECTION("case 1")
             {
                 uint8_t v[] = {'\"', 'a', 'a', 'a', 'a', 'a', 'a', '\\', 'u'};
-                CHECK_THROWS_AS(json::parse(std::begin(v), std::end(v)), json::parse_error&);
+                json _;
+                CHECK_THROWS_AS(_ = json::parse(std::begin(v), std::end(v)), json::parse_error&);
                 CHECK(!json::accept(std::begin(v), std::end(v)));
 
                 json j_error;
@@ -569,7 +571,8 @@ TEST_CASE("deserialization")
             SECTION("case 2")
             {
                 uint8_t v[] = {'\"', 'a', 'a', 'a', 'a', 'a', 'a', '\\', 'u', '1'};
-                CHECK_THROWS_AS(json::parse(std::begin(v), std::end(v)), json::parse_error&);
+                json _;
+                CHECK_THROWS_AS(_ = json::parse(std::begin(v), std::end(v)), json::parse_error&);
                 CHECK(!json::accept(std::begin(v), std::end(v)));
 
                 json j_error;
@@ -585,7 +588,8 @@ TEST_CASE("deserialization")
             SECTION("case 3")
             {
                 uint8_t v[] = {'\"', 'a', 'a', 'a', 'a', 'a', 'a', '\\', 'u', '1', '1', '1', '1', '1', '1', '1', '1'};
-                CHECK_THROWS_AS(json::parse(std::begin(v), std::end(v)), json::parse_error&);
+                json _;
+                CHECK_THROWS_AS(_ = json::parse(std::begin(v), std::end(v)), json::parse_error&);
                 CHECK(!json::accept(std::begin(v), std::end(v)));
 
                 json j_error;
@@ -601,7 +605,8 @@ TEST_CASE("deserialization")
             SECTION("case 4")
             {
                 uint8_t v[] = {'\"', 'a', 'a', 'a', 'a', 'a', 'a', 'u', '1', '1', '1', '1', '1', '1', '1', '1', '\\'};
-                CHECK_THROWS_AS(json::parse(std::begin(v), std::end(v)), json::parse_error&);
+                json _;
+                CHECK_THROWS_AS(_ = json::parse(std::begin(v), std::end(v)), json::parse_error&);
                 CHECK(!json::accept(std::begin(v), std::end(v)));
 
                 json j_error;
@@ -617,7 +622,8 @@ TEST_CASE("deserialization")
             SECTION("case 5")
             {
                 uint8_t v[] = {'\"', 0x7F, 0xC1};
-                CHECK_THROWS_AS(json::parse(std::begin(v), std::end(v)), json::parse_error&);
+                json _;
+                CHECK_THROWS_AS(_ = json::parse(std::begin(v), std::end(v)), json::parse_error&);
                 CHECK(!json::accept(std::begin(v), std::end(v)));
 
                 json j_error;
@@ -652,7 +658,8 @@ TEST_CASE("deserialization")
             SECTION("case 7")
             {
                 uint8_t v[] = {'\"', 0x7F, 0xDF, 0xC0};
-                CHECK_THROWS_AS(json::parse(std::begin(v), std::end(v)), json::parse_error&);
+                json _;
+                CHECK_THROWS_AS(_ = json::parse(std::begin(v), std::end(v)), json::parse_error&);
                 CHECK(!json::accept(std::begin(v), std::end(v)));
 
                 json j_error;
@@ -668,7 +675,8 @@ TEST_CASE("deserialization")
             SECTION("case 8")
             {
                 uint8_t v[] = {'\"', 0x7F, 0xE0, 0x9F};
-                CHECK_THROWS_AS(json::parse(std::begin(v), std::end(v)), json::parse_error&);
+                json _;
+                CHECK_THROWS_AS(_ = json::parse(std::begin(v), std::end(v)), json::parse_error&);
                 CHECK(!json::accept(std::begin(v), std::end(v)));
 
                 json j_error;
@@ -684,7 +692,8 @@ TEST_CASE("deserialization")
             SECTION("case 9")
             {
                 uint8_t v[] = {'\"', 0x7F, 0xEF, 0xC0};
-                CHECK_THROWS_AS(json::parse(std::begin(v), std::end(v)), json::parse_error&);
+                json _;
+                CHECK_THROWS_AS(_ = json::parse(std::begin(v), std::end(v)), json::parse_error&);
                 CHECK(!json::accept(std::begin(v), std::end(v)));
 
                 json j_error;
@@ -700,7 +709,8 @@ TEST_CASE("deserialization")
             SECTION("case 10")
             {
                 uint8_t v[] = {'\"', 0x7F, 0xED, 0x7F};
-                CHECK_THROWS_AS(json::parse(std::begin(v), std::end(v)), json::parse_error&);
+                json _;
+                CHECK_THROWS_AS(_ = json::parse(std::begin(v), std::end(v)), json::parse_error&);
                 CHECK(!json::accept(std::begin(v), std::end(v)));
 
                 json j_error;
@@ -716,7 +726,8 @@ TEST_CASE("deserialization")
             SECTION("case 11")
             {
                 uint8_t v[] = {'\"', 0x7F, 0xF0, 0x8F};
-                CHECK_THROWS_AS(json::parse(std::begin(v), std::end(v)), json::parse_error&);
+                json _;
+                CHECK_THROWS_AS(_ = json::parse(std::begin(v), std::end(v)), json::parse_error&);
                 CHECK(!json::accept(std::begin(v), std::end(v)));
 
                 json j_error;
@@ -732,7 +743,8 @@ TEST_CASE("deserialization")
             SECTION("case 12")
             {
                 uint8_t v[] = {'\"', 0x7F, 0xF0, 0xC0};
-                CHECK_THROWS_AS(json::parse(std::begin(v), std::end(v)), json::parse_error&);
+                json _;
+                CHECK_THROWS_AS(_ = json::parse(std::begin(v), std::end(v)), json::parse_error&);
                 CHECK(!json::accept(std::begin(v), std::end(v)));
 
                 json j_error;
@@ -748,7 +760,8 @@ TEST_CASE("deserialization")
             SECTION("case 13")
             {
                 uint8_t v[] = {'\"', 0x7F, 0xF3, 0x7F};
-                CHECK_THROWS_AS(json::parse(std::begin(v), std::end(v)), json::parse_error&);
+                json _;
+                CHECK_THROWS_AS(_ = json::parse(std::begin(v), std::end(v)), json::parse_error&);
                 CHECK(!json::accept(std::begin(v), std::end(v)));
 
                 json j_error;
@@ -764,7 +777,8 @@ TEST_CASE("deserialization")
             SECTION("case 14")
             {
                 uint8_t v[] = {'\"', 0x7F, 0xF3, 0xC0};
-                CHECK_THROWS_AS(json::parse(std::begin(v), std::end(v)), json::parse_error&);
+                json _;
+                CHECK_THROWS_AS(_ = json::parse(std::begin(v), std::end(v)), json::parse_error&);
                 CHECK(!json::accept(std::begin(v), std::end(v)));
 
                 json j_error;
@@ -780,7 +794,8 @@ TEST_CASE("deserialization")
             SECTION("case 15")
             {
                 uint8_t v[] = {'\"', 0x7F, 0xF4, 0x7F};
-                CHECK_THROWS_AS(json::parse(std::begin(v), std::end(v)), json::parse_error&);
+                json _;
+                CHECK_THROWS_AS(_ = json::parse(std::begin(v), std::end(v)), json::parse_error&);
                 CHECK(!json::accept(std::begin(v), std::end(v)));
 
                 json j_error;
@@ -796,7 +811,8 @@ TEST_CASE("deserialization")
             SECTION("case 16")
             {
                 uint8_t v[] = {'{', '\"', '\"', ':', '1', '1'};
-                CHECK_THROWS_AS(json::parse(std::begin(v), std::end(v)), json::parse_error&);
+                json _;
+                CHECK_THROWS_AS(_ = json::parse(std::begin(v), std::end(v)), json::parse_error&);
                 CHECK(!json::accept(std::begin(v), std::end(v)));
 
                 json j_error;
diff --git a/test/src/unit-ubjson.cpp b/test/src/unit-ubjson.cpp
index 42954479eca..eee8f3c79f0 100644
--- a/test/src/unit-ubjson.cpp
+++ b/test/src/unit-ubjson.cpp
@@ -798,6 +798,7 @@ TEST_CASE("UBJSON")
 
                 SECTION("errors")
                 {
+                    json _;
                     // error while parsing length
                     std::vector<uint8_t> vec0 = {'H', 'i'};
                     CHECK(json::from_ubjson(vec0, true, false).is_discarded());
@@ -806,11 +807,11 @@ TEST_CASE("UBJSON")
                     CHECK(json::from_ubjson(vec1, true, false).is_discarded());
 
                     std::vector<uint8_t> vec2 = {'H', 'i', 2, '1', 'A', '3'};
-                    CHECK_THROWS_WITH_AS(json::from_ubjson(vec2), "[json.exception.parse_error.115] parse error at byte 5: syntax error while parsing UBJSON high-precision number: invalid number text: 1A", json::parse_error);
+                    CHECK_THROWS_WITH_AS(_ = json::from_ubjson(vec2), "[json.exception.parse_error.115] parse error at byte 5: syntax error while parsing UBJSON high-precision number: invalid number text: 1A", json::parse_error);
                     std::vector<uint8_t> vec3 = {'H', 'i', 2, '1', '.'};
-                    CHECK_THROWS_WITH_AS(json::from_ubjson(vec3), "[json.exception.parse_error.115] parse error at byte 5: syntax error while parsing UBJSON high-precision number: invalid number text: 1.", json::parse_error);
+                    CHECK_THROWS_WITH_AS(_ = json::from_ubjson(vec3), "[json.exception.parse_error.115] parse error at byte 5: syntax error while parsing UBJSON high-precision number: invalid number text: 1.", json::parse_error);
                     std::vector<uint8_t> vec4 = {'H', 2, '1', '0'};
-                    CHECK_THROWS_WITH_AS(json::from_ubjson(vec4), "[json.exception.parse_error.113] parse error at byte 2: syntax error while parsing UBJSON size: expected length type specification (U, i, I, l, L) after '#'; last byte: 0x02", json::parse_error);
+                    CHECK_THROWS_WITH_AS(_ = json::from_ubjson(vec4), "[json.exception.parse_error.113] parse error at byte 2: syntax error while parsing UBJSON size: expected length type specification (U, i, I, l, L) after '#'; last byte: 0x02", json::parse_error);
                 }
 
                 SECTION("serialization")
diff --git a/test/src/unit-unicode.cpp b/test/src/unit-unicode.cpp
index 63a9d5010c7..d1b8ac9a928 100644
--- a/test/src/unit-unicode.cpp
+++ b/test/src/unit-unicode.cpp
@@ -1200,8 +1200,9 @@ TEST_CASE("Unicode" * doctest::skip())
 
         SECTION("with an iterator")
         {
+            json _;
             std::string i = "\xef\xbb\xbf{\n   \"foo\": true\n}";
-            CHECK_NOTHROW(json::parse(i.begin(), i.end()));
+            CHECK_NOTHROW(_ = json::parse(i.begin(), i.end()));
         }
     }
 

From e2889e3138919be7e4366d8cdf7d60c1ebf253b2 Mon Sep 17 00:00:00 2001
From: Thomas Braun <thomas.braun@byte-physics.de>
Date: Tue, 1 Sep 2020 13:37:36 +0200
Subject: [PATCH 2/7] Tests: Ignore some compiler warnings

Co-authored-by: James Moore <james.moore@veracityuk.com>
---
 test/src/unit-allocator.cpp            | 6 ++++++
 test/src/unit-class_const_iterator.cpp | 4 ++++
 test/src/unit-class_iterator.cpp       | 4 ++++
 test/src/unit-class_lexer.cpp          | 4 ++++
 test/src/unit-class_parser.cpp         | 4 ++++
 test/src/unit-constructor1.cpp         | 5 +++++
 test/src/unit-convenience.cpp          | 4 ++++
 test/src/unit-conversions.cpp          | 4 ++++
 test/src/unit-iterators1.cpp           | 4 ++++
 test/src/unit-json_pointer.cpp         | 6 ++++++
 test/src/unit-noexcept.cpp             | 2 ++
 test/src/unit-regression1.cpp          | 4 ++++
 test/src/unit-to_chars.cpp             | 5 +++++
 test/src/unit-unicode.cpp              | 4 ++++
 test/src/unit-user_defined_input.cpp   | 2 ++
 15 files changed, 62 insertions(+)

diff --git a/test/src/unit-allocator.cpp b/test/src/unit-allocator.cpp
index ad78b8f9ea9..df03249aeb2 100644
--- a/test/src/unit-allocator.cpp
+++ b/test/src/unit-allocator.cpp
@@ -29,6 +29,10 @@ SOFTWARE.
 
 #include "doctest_compatibility.h"
 
+#if DOCTEST_CLANG && DOCTEST_CLANG >= DOCTEST_COMPILER(3, 6, 0)
+    DOCTEST_CLANG_SUPPRESS_WARNING("-Wkeyword-macro")
+#endif // clang 3.6.x
+
 #define JSON_TESTS_PRIVATE
 #include <nlohmann/json.hpp>
 using nlohmann::json;
@@ -95,6 +99,8 @@ struct my_allocator : std::allocator<T>
     {
         if (next_deallocate_fails)
         {
+            (void)p; // Ignored unused
+            (void)n; // ignored unused
             next_deallocate_fails = false;
             throw std::bad_alloc();
         }
diff --git a/test/src/unit-class_const_iterator.cpp b/test/src/unit-class_const_iterator.cpp
index a972fd4c728..722e3518cc5 100644
--- a/test/src/unit-class_const_iterator.cpp
+++ b/test/src/unit-class_const_iterator.cpp
@@ -29,6 +29,10 @@ SOFTWARE.
 
 #include "doctest_compatibility.h"
 
+#if DOCTEST_CLANG && DOCTEST_CLANG >= DOCTEST_COMPILER(3, 6, 0)
+    DOCTEST_CLANG_SUPPRESS_WARNING("-Wkeyword-macro")
+#endif // clang 3.6.x
+
 #define JSON_TESTS_PRIVATE
 #include <nlohmann/json.hpp>
 using nlohmann::json;
diff --git a/test/src/unit-class_iterator.cpp b/test/src/unit-class_iterator.cpp
index b4ef11e436c..ff8bbf1ec5e 100644
--- a/test/src/unit-class_iterator.cpp
+++ b/test/src/unit-class_iterator.cpp
@@ -29,6 +29,10 @@ SOFTWARE.
 
 #include "doctest_compatibility.h"
 
+#if DOCTEST_CLANG && DOCTEST_CLANG >= DOCTEST_COMPILER(3, 6, 0)
+    DOCTEST_CLANG_SUPPRESS_WARNING("-Wkeyword-macro")
+#endif // clang 3.6.x
+
 #define JSON_TESTS_PRIVATE
 #include <nlohmann/json.hpp>
 using nlohmann::json;
diff --git a/test/src/unit-class_lexer.cpp b/test/src/unit-class_lexer.cpp
index 1a4f8ed7541..0d7e49799d8 100644
--- a/test/src/unit-class_lexer.cpp
+++ b/test/src/unit-class_lexer.cpp
@@ -29,6 +29,10 @@ SOFTWARE.
 
 #include "doctest_compatibility.h"
 
+#if DOCTEST_CLANG && DOCTEST_CLANG >= DOCTEST_COMPILER(3, 6, 0)
+    DOCTEST_CLANG_SUPPRESS_WARNING("-Wkeyword-macro")
+#endif // clang 3.6.x
+
 #define JSON_TESTS_PRIVATE
 #include <nlohmann/json.hpp>
 using nlohmann::json;
diff --git a/test/src/unit-class_parser.cpp b/test/src/unit-class_parser.cpp
index d0335c94847..274b7955bbb 100644
--- a/test/src/unit-class_parser.cpp
+++ b/test/src/unit-class_parser.cpp
@@ -29,6 +29,10 @@ SOFTWARE.
 
 #include "doctest_compatibility.h"
 
+#if DOCTEST_CLANG && DOCTEST_CLANG >= DOCTEST_COMPILER(3, 6, 0)
+    DOCTEST_CLANG_SUPPRESS_WARNING("-Wkeyword-macro")
+#endif // clang 3.6.x
+
 #define JSON_TESTS_PRIVATE
 #include <nlohmann/json.hpp>
 using nlohmann::json;
diff --git a/test/src/unit-constructor1.cpp b/test/src/unit-constructor1.cpp
index 70b3e40470d..8509fa1e325 100644
--- a/test/src/unit-constructor1.cpp
+++ b/test/src/unit-constructor1.cpp
@@ -28,8 +28,13 @@ SOFTWARE.
 */
 
 #include "doctest_compatibility.h"
+
 DOCTEST_GCC_SUPPRESS_WARNING("-Wfloat-equal")
 
+#if DOCTEST_CLANG && DOCTEST_CLANG >= DOCTEST_COMPILER(3, 6, 0)
+    DOCTEST_CLANG_SUPPRESS_WARNING("-Wkeyword-macro")
+#endif // clang 3.6.x
+
 #define JSON_TESTS_PRIVATE
 #include <nlohmann/json.hpp>
 using nlohmann::json;
diff --git a/test/src/unit-convenience.cpp b/test/src/unit-convenience.cpp
index c75edac4ead..14b93245137 100644
--- a/test/src/unit-convenience.cpp
+++ b/test/src/unit-convenience.cpp
@@ -29,6 +29,10 @@ SOFTWARE.
 
 #include "doctest_compatibility.h"
 
+#if DOCTEST_CLANG && DOCTEST_CLANG >= DOCTEST_COMPILER(3, 6, 0)
+    DOCTEST_CLANG_SUPPRESS_WARNING("-Wkeyword-macro")
+#endif // clang 3.6.x
+
 #define JSON_TESTS_PRIVATE
 #include <nlohmann/json.hpp>
 using nlohmann::json;
diff --git a/test/src/unit-conversions.cpp b/test/src/unit-conversions.cpp
index c71e230d964..e4deb7e037a 100644
--- a/test/src/unit-conversions.cpp
+++ b/test/src/unit-conversions.cpp
@@ -29,6 +29,10 @@ SOFTWARE.
 
 #include "doctest_compatibility.h"
 
+#if DOCTEST_CLANG && DOCTEST_CLANG >= DOCTEST_COMPILER(3, 6, 0)
+    DOCTEST_CLANG_SUPPRESS_WARNING("-Wkeyword-macro")
+#endif // clang 3.6.x
+
 #define JSON_TESTS_PRIVATE
 #include <nlohmann/json.hpp>
 using nlohmann::json;
diff --git a/test/src/unit-iterators1.cpp b/test/src/unit-iterators1.cpp
index 1ff8958fad5..90743d26507 100644
--- a/test/src/unit-iterators1.cpp
+++ b/test/src/unit-iterators1.cpp
@@ -29,6 +29,10 @@ SOFTWARE.
 
 #include "doctest_compatibility.h"
 
+#if DOCTEST_CLANG && DOCTEST_CLANG >= DOCTEST_COMPILER(3, 6, 0)
+    DOCTEST_CLANG_SUPPRESS_WARNING("-Wkeyword-macro")
+#endif // clang 3.6.x
+
 #define JSON_TESTS_PRIVATE
 #include <nlohmann/json.hpp>
 using nlohmann::json;
diff --git a/test/src/unit-json_pointer.cpp b/test/src/unit-json_pointer.cpp
index 14d8cd18300..a076baa7138 100644
--- a/test/src/unit-json_pointer.cpp
+++ b/test/src/unit-json_pointer.cpp
@@ -29,6 +29,12 @@ SOFTWARE.
 
 #include "doctest_compatibility.h"
 
+DOCTEST_MSVC_SUPPRESS_WARNING(4127)
+
+#if DOCTEST_CLANG && DOCTEST_CLANG >= DOCTEST_COMPILER(3, 6, 0)
+    DOCTEST_CLANG_SUPPRESS_WARNING("-Wkeyword-macro")
+#endif // clang 3.6.x
+
 #define JSON_TESTS_PRIVATE
 #include <nlohmann/json.hpp>
 using nlohmann::json;
diff --git a/test/src/unit-noexcept.cpp b/test/src/unit-noexcept.cpp
index 7e657bf9fb1..9f4b63f775b 100644
--- a/test/src/unit-noexcept.cpp
+++ b/test/src/unit-noexcept.cpp
@@ -31,6 +31,8 @@ SOFTWARE.
 
 #include <nlohmann/json.hpp>
 
+DOCTEST_CLANG_SUPPRESS_WARNING("-Wunneeded-internal-declaration")
+
 using nlohmann::json;
 
 namespace
diff --git a/test/src/unit-regression1.cpp b/test/src/unit-regression1.cpp
index 9dcc75b0920..03f3561279b 100644
--- a/test/src/unit-regression1.cpp
+++ b/test/src/unit-regression1.cpp
@@ -30,6 +30,10 @@ SOFTWARE.
 #include "doctest_compatibility.h"
 DOCTEST_GCC_SUPPRESS_WARNING("-Wfloat-equal")
 
+#if DOCTEST_CLANG && DOCTEST_CLANG >= DOCTEST_COMPILER(3, 6, 0)
+    DOCTEST_CLANG_SUPPRESS_WARNING("-Wkeyword-macro")
+#endif // clang 3.6.x
+
 // for some reason including this after the json header leads to linker errors with VS 2017...
 #include <locale>
 
diff --git a/test/src/unit-to_chars.cpp b/test/src/unit-to_chars.cpp
index 2861928f8f3..68587d97628 100644
--- a/test/src/unit-to_chars.cpp
+++ b/test/src/unit-to_chars.cpp
@@ -33,6 +33,11 @@ SOFTWARE.
 
 #include "doctest_compatibility.h"
 
+#if (DOCTEST_GCC >= DOCTEST_COMPILER(4, 8, 0)) && \
+    (DOCTEST_GCC < DOCTEST_COMPILER(5, 0, 0))
+    DOCTEST_GCC_SUPPRESS_WARNING("-Wmissing-field-initializers")
+#endif // gcc 4.8.x and 4.9.x
+
 #include <nlohmann/json.hpp>
 using nlohmann::detail::dtoa_impl::reinterpret_bits;
 
diff --git a/test/src/unit-unicode.cpp b/test/src/unit-unicode.cpp
index d1b8ac9a928..4b41d147274 100644
--- a/test/src/unit-unicode.cpp
+++ b/test/src/unit-unicode.cpp
@@ -29,6 +29,10 @@ SOFTWARE.
 
 #include "doctest_compatibility.h"
 
+#if DOCTEST_CLANG && DOCTEST_CLANG >= DOCTEST_COMPILER(3, 6, 0)
+    DOCTEST_CLANG_SUPPRESS_WARNING("-Wkeyword-macro")
+#endif // clang 3.6.x
+
 // for some reason including this after the json header leads to linker errors with VS 2017...
 #include <locale>
 
diff --git a/test/src/unit-user_defined_input.cpp b/test/src/unit-user_defined_input.cpp
index 5a1138b0049..28ee9749010 100644
--- a/test/src/unit-user_defined_input.cpp
+++ b/test/src/unit-user_defined_input.cpp
@@ -29,6 +29,8 @@ SOFTWARE.
 
 #include "doctest_compatibility.h"
 
+DOCTEST_GCC_SUPPRESS_WARNING("-Wunused-local-typedefs")
+
 #include <nlohmann/json.hpp>
 using nlohmann::json;
 

From 077122629cb7e59500ca45561b7c6f7b62834f23 Mon Sep 17 00:00:00 2001
From: Thomas Braun <thomas.braun@byte-physics.de>
Date: Tue, 7 Jul 2020 22:53:34 +0200
Subject: [PATCH 3/7] unit-allocator.cpp: Silence compiler warning on MSVC 2015

---
 test/src/unit-allocator.cpp | 1 +
 test/src/unit-udt.cpp       | 4 +++-
 2 files changed, 4 insertions(+), 1 deletion(-)

diff --git a/test/src/unit-allocator.cpp b/test/src/unit-allocator.cpp
index df03249aeb2..68a37106995 100644
--- a/test/src/unit-allocator.cpp
+++ b/test/src/unit-allocator.cpp
@@ -114,6 +114,7 @@ struct my_allocator : std::allocator<T>
     {
         if (next_destroy_fails)
         {
+            (void)p; // Ignored unused
             next_destroy_fails = false;
             throw std::bad_alloc();
         }
diff --git a/test/src/unit-udt.cpp b/test/src/unit-udt.cpp
index 7f74ac5f8bb..7e5d1066eca 100644
--- a/test/src/unit-udt.cpp
+++ b/test/src/unit-udt.cpp
@@ -817,7 +817,9 @@ class Evil
   public:
     Evil() = default;
     template <typename T>
-    Evil(T t) : m_i(sizeof(t)) {}
+    Evil(T t) : m_i(sizeof(t)) {
+      (void)t; // Ignored unused
+    }
 
     int m_i = 0;
 };

From 0b8644c452d864dc88d801ce55b47207051857d7 Mon Sep 17 00:00:00 2001
From: Thomas Braun <thomas.braun@byte-physics.de>
Date: Tue, 1 Sep 2020 13:36:55 +0200
Subject: [PATCH 4/7] test/CMakeLists.txt: Use more fine grained compiler
 detection

Clang on Windows comes in two flavours, one which pretens to be like GCC
and one which pretends to be like MSVC. We need to distinguish these two
so that we can pass the correct compiler flags.

Co-authored-by: James Moore <james.moore@veracityuk.com>
---
 test/CMakeLists.txt | 23 +++++++++++++++++++----
 1 file changed, 19 insertions(+), 4 deletions(-)

diff --git a/test/CMakeLists.txt b/test/CMakeLists.txt
index 3d8bceb70c6..403bd0402d4 100644
--- a/test/CMakeLists.txt
+++ b/test/CMakeLists.txt
@@ -142,6 +142,18 @@ set(files
     src/unit-user_defined_input.cpp
     src/unit-wstring.cpp)
 
+set(CLANG_AS_MSVC 0)
+set(MSVC_LIKE 0)
+
+if(CMAKE_CXX_COMPILER_ID STREQUAL "MSVC")
+  set(MSVC_LIKE 1)
+elseif(CMAKE_CXX_SIMULATE_ID STREQUAL "MSVC"
+       AND CMAKE_CXX_COMPILER_ID STREQUAL "Clang"
+       AND CMAKE_GENERATOR MATCHES "Visual Studio")
+  set(MSVC_LIKE 1)
+  set(CLANG_AS_MSVC 1)
+endif()
+
 foreach(file ${files})
     get_filename_component(file_basename ${file} NAME_WE)
     string(REGEX REPLACE "unit-([^$]+)" "test-\\1" testcase ${file_basename})
@@ -149,10 +161,12 @@ foreach(file ${files})
     add_executable(${testcase} $<TARGET_OBJECTS:doctest_main> ${file})
     target_compile_definitions(${testcase} PRIVATE DOCTEST_CONFIG_SUPER_FAST_ASSERTS)
     target_compile_options(${testcase} PRIVATE
-        $<$<CXX_COMPILER_ID:MSVC>:/EHsc;$<$<CONFIG:Release>:/Od>>
-        $<$<NOT:$<CXX_COMPILER_ID:MSVC>>:-Wno-deprecated;-Wno-float-equal>
+        $<${MSVC_LIKE}:/EHsc;/W4;/WX;$<$<CONFIG:Release>:/Od>>
+        $<$<NOT:${MSVC_LIKE}>:-Wno-deprecated;-Wno-float-equal;-Wall;-Wextra;-pedantic;-Werror>
         $<$<CXX_COMPILER_ID:GNU>:-Wno-deprecated-declarations>
+        $<${CLANG_AS_MSVC}:/clang:-Wno-deprecated;/clang:-pedantic;/clang:-Wno-deprecated-declarations;-Wno-float-equal>
     )
+
     target_include_directories(${testcase} PRIVATE ${CMAKE_BINARY_DIR}/include thirdparty/doctest thirdparty/fifo_map)
     target_link_libraries(${testcase} PRIVATE ${NLOHMANN_JSON_TARGET_NAME})
 
@@ -179,9 +193,10 @@ endforeach()
 add_executable(json_unit EXCLUDE_FROM_ALL $<TARGET_OBJECTS:doctest_main> ${files})
 target_compile_definitions(json_unit PRIVATE DOCTEST_CONFIG_SUPER_FAST_ASSERTS)
 target_compile_options(json_unit PRIVATE
-    $<$<CXX_COMPILER_ID:MSVC>:/EHsc;$<$<CONFIG:Release>:/Od>>
-    $<$<NOT:$<CXX_COMPILER_ID:MSVC>>:-Wno-deprecated;-Wno-float-equal>
+    $<${MSVC_LIKE}:/EHsc;$<$<CONFIG:Release>:/Od>>
+    $<$<NOT:${MSVC_LIKE}>:-Wno-deprecated;-Wno-float-equal>
     $<$<CXX_COMPILER_ID:GNU>:-Wno-deprecated-declarations>
+    $<${CLANG_AS_MSVC}:/clang:-Wno-deprecated-declarations>
 )
 target_include_directories(json_unit PRIVATE ${CMAKE_BINARY_DIR}/include thirdparty/doctest thirdparty/fifo_map)
 target_link_libraries(json_unit ${NLOHMANN_JSON_TARGET_NAME})

From f907c2ac2de2d7ee35565ecb8d80731f50b6a49e Mon Sep 17 00:00:00 2001
From: Thomas Braun <thomas.braun@byte-physics.de>
Date: Tue, 1 Sep 2020 13:31:01 +0200
Subject: [PATCH 5/7] unit-deserialization.cpp: Silence MSVC compiler warning

---
 test/src/unit-deserialization.cpp | 4 ++++
 1 file changed, 4 insertions(+)

diff --git a/test/src/unit-deserialization.cpp b/test/src/unit-deserialization.cpp
index d2db7e80c3d..ce58f31db46 100644
--- a/test/src/unit-deserialization.cpp
+++ b/test/src/unit-deserialization.cpp
@@ -29,6 +29,10 @@ SOFTWARE.
 
 #include "doctest_compatibility.h"
 
+#if DOCTEST_MSVC && DOCTEST_MSVC < DOCTEST_COMPILER(19, 20, 0)
+DOCTEST_MSVC_SUPPRESS_WARNING(4309) // 'conversion' : truncation of constant value
+#endif // VS 14 2015 and 15 2017
+
 #include <nlohmann/json.hpp>
 using nlohmann::json;
 

From 435c7f849810691bab57d8e29998450a4f7e75ed Mon Sep 17 00:00:00 2001
From: Thomas Braun <thomas.braun@byte-physics.de>
Date: Tue, 1 Sep 2020 13:33:53 +0200
Subject: [PATCH 6/7] unit-items.cpp: Silence clang compiler warnings

---
 test/src/unit-items.cpp | 8 ++++++++
 1 file changed, 8 insertions(+)

diff --git a/test/src/unit-items.cpp b/test/src/unit-items.cpp
index 10621ce7e95..7cddd93bff7 100644
--- a/test/src/unit-items.cpp
+++ b/test/src/unit-items.cpp
@@ -39,6 +39,14 @@ using nlohmann::json;
     #define JSON_HAS_CPP_14
 #endif
 
+#if defined(DOCTEST_PLATFORM_WINDOWS) && defined(DOCTEST_CLANG) && DOCTEST_CLANG >= DOCTEST_COMPILER(10, 0, 0)
+    DOCTEST_CLANG_SUPPRESS_WARNING("-Wrange-loop-construct")
+// work around misdetection of platform on MacOSX Big Sur, this should be DOCTEST_PLATFORM_MAC
+// see also https://github.com/onqtam/doctest/issues/415
+#elif defined(DOCTEST_PLATFORM_LINUX) && defined(DOCTEST_CLANG) && DOCTEST_CLANG >= DOCTEST_COMPILER(12, 0, 0)
+    DOCTEST_CLANG_SUPPRESS_WARNING("-Wrange-loop-analysis")
+#endif
+
 TEST_CASE("iterator_wrapper")
 {
     SECTION("object")

From e2264601542bd29a88fc85570b95c4e897eb2781 Mon Sep 17 00:00:00 2001
From: Thomas Braun <thomas.braun@byte-physics.de>
Date: Tue, 1 Sep 2020 13:44:37 +0200
Subject: [PATCH 7/7] github/actions: Remove clang9 on Windows

This currently produces

 In file included from C:\Program Files (x86)\Microsoft Visual Studio\2019\Enterprise\VC\Tools\MSVC\14.27.29110\include\ciso646:9:
 In file included from C:\Program Files (x86)\Microsoft Visual Studio\2019\Enterprise\VC\Tools\MSVC\14.27.29110\include\yvals.h:9:
 C:\Program Files (x86)\Microsoft Visual Studio\2019\Enterprise\VC\Tools\MSVC\14.27.29110\include\yvals_core.h:494:2: error: STL1000: Unexpected compiler version, expected Clang 10.0.0 or newer.
  #error STL1000: Unexpected compiler version, expected Clang 10.0.0 or newer.

and that is very likely due to the new -pedantic flag when compiling.

Let's remove this compiler as it clearly is not meant to be used with
these MSVC headers.
---
 .github/workflows/windows.yml | 14 --------------
 1 file changed, 14 deletions(-)

diff --git a/.github/workflows/windows.yml b/.github/workflows/windows.yml
index 5846cf7500e..1778c941829 100644
--- a/.github/workflows/windows.yml
+++ b/.github/workflows/windows.yml
@@ -15,20 +15,6 @@ jobs:
     - name: test
       run: cd build ; ctest -j 10 -C Debug --exclude-regex "test-unicode" --output-on-failure
 
-  clang9:
-    runs-on: windows-latest
-
-    steps:
-      - uses: actions/checkout@v1
-      - name: install Clang
-        run: curl -fsSL -o LLVM9.exe https://releases.llvm.org/9.0.0/LLVM-9.0.0-win64.exe ; 7z x LLVM9.exe -y -o"C:/Program Files/LLVM"
-      - name: cmake
-        run: cmake -S . -B build -DCMAKE_CXX_COMPILER="C:/Program Files/LLVM/bin/clang++.exe" -G"MinGW Makefiles" -DCMAKE_BUILD_TYPE=Debug -DJSON_BuildTests=On
-      - name: build
-        run: cmake --build build --parallel 10
-      - name: test
-        run: cd build ; ctest -j 10 -C Debug --exclude-regex "test-unicode" --output-on-failure
-
   clang10:
     runs-on: windows-latest