diff options
Diffstat (limited to 'absl/base/attributes.h')
| -rw-r--r-- | absl/base/attributes.h | 25 |
1 files changed, 18 insertions, 7 deletions
diff --git a/absl/base/attributes.h b/absl/base/attributes.h index c44b8828509a..291ad89ee782 100644 --- a/absl/base/attributes.h +++ b/absl/base/attributes.h @@ -402,17 +402,28 @@ // ABSL_MUST_USE_RESULT // -// Tells the compiler to warn about unused return values for functions declared -// with this macro. The macro must appear as the very first part of a function -// declaration or definition: +// Tells the compiler to warn about unused results. // -// Example: +// When annotating a function, it must appear as the first part of the +// declaration or definition. The compiler will warn if the return value from +// such a function is unused: // // ABSL_MUST_USE_RESULT Sprocket* AllocateSprocket(); +// AllocateSprocket(); // Triggers a warning. +// +// When annotating a class, it is equivalent to annotating every function which +// returns an instance. +// +// class ABSL_MUST_USE_RESULT Sprocket {}; +// Sprocket(); // Triggers a warning. +// +// Sprocket MakeSprocket(); +// MakeSprocket(); // Triggers a warning. +// +// Note that references and pointers are not instances: // -// This placement has the broadest compatibility with GCC, Clang, and MSVC, with -// both defs and decls, and with GCC-style attributes, MSVC declspec, C++11 -// and C++17 attributes. +// Sprocket* SprocketPointer(); +// SprocketPointer(); // Does *not* trigger a warning. // // ABSL_MUST_USE_RESULT allows using cast-to-void to suppress the unused result // warning. For that, warn_unused_result is used only for clang but not for gcc. |