https://gcc.gnu.org/bugzilla/show_bug.cgi?id=69462
Bug ID: 69462
Summary: FLT_EVAL_METHOD and DECIMAL_DIG missing in float.h
Product: gcc
Version: 6.0
Status: UNCONFIRMED
Severity: normal
Priority: P3
Component: c++
Assignee: unassigned at gcc dot gnu.org
Reporter: vogt at linux dot vnet.ibm.com
Target Milestone: ---
The macros FLT_EVAL_METHOD and DECIMAL_DIG (required by C++-11, maybe earlier)
are present when including cfloat but not when including float.h:
-- y.C --
#include <float.h>
int x = FLT_EVAL_METHOD;
int y = DECIMAL_DIG;
---------
-- z.C --
#include <cfloat>
int x = FLT_EVAL_METHOD;
int y = DECIMAL_DIG;
---------
==>
$ g++ -std=c++11 z.C -S && echo ok
ok
$ g++ -std=c++11 y.C -S
y.C:2:9: error: 'FLT_EVAL_METHOD' was not declared in this scope
...
y.C:3:9: error: 'DECIMAL_DIG' was not declared in this scope
...
--
cfloat has this bit of code that is missing from float.h:
-- snip --
#ifndef _GLIBCXX_CFLOAT
#define _GLIBCXX_CFLOAT 1
#if __cplusplus >= 201103L
# ifndef DECIMAL_DIG
# define DECIMAL_DIG __DECIMAL_DIG__
# endif
# ifndef FLT_EVAL_METHOD
# define FLT_EVAL_METHOD __FLT_EVAL_METHOD__
# endif
#endif
#endif
-- snip --
