arene-base provides facilities for uniformly suppressing compiler diagnostics in a cross-compiler manner without exposing #pragma to user code. The public header is:

#include "arene/base/compiler_support/diagnostics.hpp"

Provides macros used to disable and enable compiler specific diagnostics using the _Pragma operator.

Warning: Users should only use the facilities discussed below with proper justification. Compiler diagnostics should not be suppressed without specific, documented justification, such as working around a compiler bug, or unit testing error handling for behavior that would otherwise be prevented by non-default compiler diagnostics. They should never be suppressed in order to land code without resolving the warning to meet deadlines.

Suppressing Compiler Diagnostics

The process for suppressing one or more diagnostics is as follows:

Invoke the ARENE_IGNORE_START() macro.
Invoke ARENE_IGNORE_XXX(diagnostic, rational) macros as appropraite. ALWAYS INCLUDE JUSTIFICATION IN THE RATIONAL FIELD!.
Execute the statements which need diagnostic suppression.
Invoke the ARENE_IGNORE_END() macro.

The amount of code contained between ARENE_IGNORE_START() and ARENE_IGNORE_END() should be the minimum amount of logic possible. Do not simply suppress diagnostics at the start of a source file and disable them at the end.

Example usage of suppressing -Wfloat-equal in an implementation where an exact floating point comparison to the precise value of positive zero is desired:

ARENE_IGNORE_START();
ARENE_IGNORE_ALL(
    "-Wfloat-equal",
    "In this situation testing for exact equality to zero to handle edge cases with NaN and Inf in floats.");
/// @brief Calculate the absolute value of a 32-bit or 64-bit floating number.
/// @param value
/// @returns The absolute value of @c value .
template <class Number, constraints<std::enable_if_t<(std::is_floating_point<Number>::value)>> = nullptr>
constexpr Number abs(Number value) noexcept {
  constexpr auto zero = static_cast<Number>(0);
  return value < zero ? -value : (value == zero ? zero : (value > zero ? value : -value));
}
ARENE_IGNORE_END();

Supported Suppression Macros

Macro	Description
`ARENE_IGNORE_GCC(s, comment)`	The diagnostic should only be attempted to be suppressed when compiling with `gcc`
`ARENE_IGNORE_CLANG(s, comment)`	The diagnostic should only be attempted to be suppressed when compiling with `clang`
`ARENE_IGNORE_ALL(s, comment)`	The diagnostic should always be attempted to be suppressed

Note: Currently, ARENE_IGNORE_ALL only supports clang and gcc.

Warning: If a diagnostic is passed to ARENE_IGNORE_ALL which is unknown to the current compiler, this generally will result in a compiler error. Only use this when you are positive that the given diagnostic name is the same across all compilers.