Rollup of 7 pull requests#65878

Closed

Centril wants to merge 19 commits intorust-lang:masterfrom

Centril:rollup-frxkcrv

Commits on Aug 24, 2019

Add 'must_use' to all functions 'fn(float) -> float'
Kyle Strand
committed

Commits on Aug 28, 2019

Add reason for each 'must_use'
Kyle Strand
committed
Annotate functions taking extra args
Kyle Strand
committed
Let 'clamp' be invoked without using return value; used in tests
Kyle Strand
committed

Commits on Sep 5, 2019

Restore 'must_use' for 'clamp'; fix warning for tests
Kyle Strand
committed

Commits on Oct 19, 2019

Stabilize `Option::flatten`
eopb
committed

Commits on Oct 27, 2019