There's a comment from 2002 suggesting that
numeric_limits<bool>::traps was in a DR, but C++ standards including
11, 17 and 23 explicitly set it to false, presumably in response to
issue 184.
Issue 554 clarifies that traps is about values that may trap, rather
than operations that may trap, so we were wrong in the interpretation
about divide-by-zero operations' trapping on integral types that led
to __glibcxx_integral_traps's defaulting to true, and some of its
overrides.
Align numeric_limits<bool>::traps with the standard, default
__glibcxx_integral_traps to false, drop the overriders based on the
incorrect interpretation, but keep __glibcxx_integral_traps to allow
command-line restoring of this ABI fix, and for the admittedly
unlikely case of trapping integral values' coming to exist on some
architecture.
for libstdc++-v3/ChangeLog
* include/std/limits (__glibcxx_integral_traps): Set to
false. Update comments.
(numeric_limits<bool>::traps): Drop comments.
* config/cpu/arm/cpu_defines.h: Remove.
* config/cpu/powerpc/cpu_defines.h: Likewise.
* configure.host (cpu_defines_dir): Adjust.
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