The header
defines loads of macros. As such it is an omnipresent header that is included in many other headers. Being a C99 header, some macros are disabled in C++. One example are the
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| INT8_C, INT16_C, INT32_c and INT64_C |
INT8_C, INT16_C, INT32_c and INT64_C
macros. When looking at the header (see below) one sees that the macros can be enabled in C++ by defining
.
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| /* The ISO C99 standard specifies that in C++ implementations these
should only be defined if explicitly requested. */
#if !defined __cplusplus || defined __STDC_CONSTANT_MACROS
/* Signed. */
# define INT8_C(c) c
# define INT16_C(c) c
# define INT32_C(c) c
# if __WORDSIZE == 64
# define INT64_C(c) c ## L
# else
# define INT64_C(c) c ## LL
# endif
...
#endif |
/* The ISO C99 standard specifies that in C++ implementations these
should only be defined if explicitly requested. */
#if !defined __cplusplus || defined __STDC_CONSTANT_MACROS
/* Signed. */
# define INT8_C(c) c
# define INT16_C(c) c
# define INT32_C(c) c
# if __WORDSIZE == 64
# define INT64_C(c) c ## L
# else
# define INT64_C(c) c ## LL
# endif
...
#endif
When i tried this in some C++ file in my project, it didn’t fix the
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| error: ‘UINT64_C’ was not declared in this scope |
error: ‘UINT64_C’ was not declared in this scope
. I realized that the header has already been included before I defined
. Due the the header guard the define has no effect. To fix this problem I simply undef the header guard.
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| #define __STDC_CONSTANT_MACROS
#ifdef _STDINT_H
# undef _STDINT_H
#endif
# include <stdint.h> |
#define __STDC_CONSTANT_MACROS
#ifdef _STDINT_H
# undef _STDINT_H
#endif
# include <stdint.h>
Of course this trick does not work for all header but in the case of
it works because this header only defines macros.
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