[edit]Types

The implementation may define typedef namesintN_t,int_fastN_t,int_leastN_t,uintN_t,uint_fastN_t, anduint_leastN_t whenN is not 8, 16, 32 or 64. Typedef names of the formintN_t may only be defined if the implementation supports an integer type of that width with no padding. Thus,std::uint24_t denotes an unsigned integer type with a width of exactly 24 bits.

Each of the macros listed in below is defined if and only if the implementation defines the corresponding typedef name. The macrosINTN_C andUINTN_C correspond to the typedef namesint_leastN_t anduint_leastN_t, respectively.

[edit]Macro constants

[edit]Function macros for minimum-width integer constants

#include <cstdint>UINT64_C(0x123)// expands to a literal of type uint_least64_t and value 0x123

[edit]Format macro constants

[edit]Format constants for thestd::fprintf family of functions

Each of thePRI macros listed here is defined if and only if the implementation defines the corresponding typedef name.

[edit]Format constants for thestd::fscanf family of functions

Each of theSCN macros listed in here is defined if and only if the implementation defines the corresponding typedef name and has a suitablestd::fscanf length modifier for the type.

[edit]Notes

Because C++ interprets a character immediately following a string literal as auser-defined string literal, C code such asprintf("%"PRId64"\n",n); is invalid C++ and requires a space beforePRId64.

The C99 standard suggests that C++ implementations should not define the above limit, constant, or format macros unless the macros__STDC_LIMIT_MACROS,__STDC_CONSTANT_MACROS or__STDC_FORMAT_MACROS (respectively) are defined before including the relevant C header (stdint.h orinttypes.h). This recommendation was not adopted by any C++ standard and was removed in C11. However, some implementations (such as glibc 2.17) try to apply this rule, and it may be necessary to define the__STDC macros; C++ compilers may try to work around this by automatically defining them in some circumstances.

std::int8_t may besignedchar andstd::uint8_t may beunsignedchar, but neither can bechar regardless of its signedness (becausechar is not considered a "signed integer type" or "unsigned integer type").

[edit]Example

#include <cinttypes>#include <cstdio> int main(){std::printf("%zu\n", sizeof(std::int64_t));std::printf("%s\n", PRId64);std::printf("%+" PRId64"\n", INT64_MIN);std::printf("%+" PRId64"\n", INT64_MAX);     std::int64_t n=7;std::printf("%+" PRId64"\n", n);}

8lld-9223372036854775808+9223372036854775807+7

[edit]Defect reports

The following behavior-changing defect reports were applied retroactively to previously published C++ standards.

[edit]References

[edit]See also

• Fundamental types

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