Merge pull request #479 from lsst-dm/u/ktl/update-macosx-platforms

Update list of macOS platforms.

Author: ktlim

cpp/style.rst

@@ -93,6 +93,7 @@ We follow the official: International Standard ISO/IEC 14882:2017(E) – Program
 
    We use compilers provided by a specific :ref:`Conda environment <platforms-environment>` executing on a defined :ref:`baseline platform <platforms-baseline>`.
    This environment provides complete support for C++17, but --- in the case of compiler bugs --- the allowed set of C++17 features is those which can be shown to work properly in this reference environment.
+   In practice, we further restrict the feature set to those that also work on our commonly-tested platforms.
 
 The C++17 standard adds a number of useful features such as nested namespace definitions, structured binding declarations, initializers in ``if`` and ``switch`` statements, class template argument deduction, ``std::optional``, ``std::any``, ``std::filesystem``, and ``std::variant``.
 A parallel algorithms library has also been added, although use of this in Science Pipelines code should be vetted, as we typically use one-core-per-process parallelization.

stack/platforms.rst

@@ -24,11 +24,11 @@ The baseline platform is currently CentOS 7 on Intel x86_64.
 
 We regularly test the following platforms in addition to the baseline platform:
 
-* macOS Mojave (10.14);
-* macOS High Sierra (10.13).
+* macOS Big Sur (11.0);
+* macOS Catalina (10.15).
 
 See https://ci.lsst.codes for the current list of regularly-tested platforms.
-(The "osx" platform there for the "stack-os-matrix" job randomly chooses a Mojave or High Sierra machine for each execution to limit load.)
+(The "osx" platform there for the "stack-os-matrix" job randomly chooses a Big Sur or Catalina machine for each execution to limit load.)
 
 .. _platforms-environment: