root-project
RtypesCore.h does not have a signed character type
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Description
The Char_t typedef here:
https://github.com/root-project/root/blob/4cf09dc362036e22eaa687cd2566fabb6c8ed693/core/foundation/inc/RtypesCore.h#L37
is incorrect--a bare char is not guaranteed to be signed or unsigned.
char — type for character representation which can be most efficiently processed on the target system (has the same representation and alignment as either signed char or unsigned char, but is always a distinct type). Multibyte characters strings use this type to represent code units. For every value of type unsigned char in range [0, 255], converting the value to char and then back to unsigned char produces the original value.(since C++11) The signedness of char depends on the compiler and the target platform: the defaults for ARM and PowerPC are typically unsigned, the defaults for x86 and x64 are typically signed.
To actually guarantee to be a signed type, Char_t would have to be declared as signed char.
From another issue, it appears ROOT is moving away from Rtypes.h since the C++ standard has a evolved a more complete type system, so this may be a "who cares" issue...
Reproducer
n/a
ROOT version
latest
Installation method
n/a
Operating system
n/a
Additional context
No response
Related:
https://github.com/root-project/root/issues/12208 https://github.com/root-project/root/issues/7565
