The page https://en.cppreference.com/w/cpp/numeric/math/fabs mentions that std::fabsf is available since C++11. However, when I use G++ 6.3.0 to compile even the simplest program that uses std::fabsf, it says that fabsf is not a member of std.
#include <cmath>
int main()
{
return (int)std::fabsf(0.0f);
}
Which one is right? Is G++ 6.3.0 wrong in not including it in std, or is the above page wrong in mentioning it as part of std in C++11?
And if it's G++ that is wrong, is that fixed in later versions?
Yes, fabsf and all other -f/-l functions from math.h is part of the std namespace via cmath in C++11. It was added in about 2002, when C++0x was rebased on top of the C99 standard library, which made [c.math]/4 include those new functions.
[c.math]/4The contents of these headers are the same as the Standard C library headers
<math.h>and<stdlib.h>respectively, with the following changes:
(historical note: the intent to add all the -f/-l variants was already apparent in C++03, see LWG289)
However, the table listing the contents of cmath was overlooked until 2016, when p0175r1 fixed all such tables to bring them in line with the standard.
p0175r1Impact on the standard
The change is purely editorial.