long数据类型跨平台问题

源代码

#include <iostream>

int main()
{
	std::cout << "size of long : " << sizeof(long) << std::endl;
	return 0;
}

Windows

long -> 32位

Linux

long -> 64位

建议

跨平台程序尽量采用跨平台库，如Boost

namespace boost
{

  using ::int8_t;
  using ::int_least8_t;
  using ::int_fast8_t;
  using ::uint8_t;
  using ::uint_least8_t;
  using ::uint_fast8_t;

  using ::int16_t;
  using ::int_least16_t;
  using ::int_fast16_t;
  using ::uint16_t;
  using ::uint_least16_t;
  using ::uint_fast16_t;

  using ::int32_t;
  using ::int_least32_t;
  using ::int_fast32_t;
  using ::uint32_t;
  using ::uint_least32_t;
  using ::uint_fast32_t;

# ifndef BOOST_NO_INT64_T

  using ::int64_t;
  using ::int_least64_t;
  using ::int_fast64_t;
  using ::uint64_t;
  using ::uint_least64_t;
  using ::uint_fast64_t;

# endif

  using ::intmax_t;
  using ::uintmax_t;

}

或者stdint.h

typedef signed char        int8_t;
typedef short              int16_t;
typedef int                int32_t;
typedef long long          int64_t;
typedef unsigned char      uint8_t;
typedef unsigned short     uint16_t;
typedef unsigned int       uint32_t;
typedef unsigned long long uint64_t;

typedef signed char        int_least8_t;
typedef short              int_least16_t;
typedef int                int_least32_t;
typedef long long          int_least64_t;
typedef unsigned char      uint_least8_t;
typedef unsigned short     uint_least16_t;
typedef unsigned int       uint_least32_t;
typedef unsigned long long uint_least64_t;

typedef signed char        int_fast8_t;
typedef int                int_fast16_t;
typedef int                int_fast32_t;
typedef long long          int_fast64_t;
typedef unsigned char      uint_fast8_t;
typedef unsigned int       uint_fast16_t;
typedef unsigned int       uint_fast32_t;
typedef unsigned long long uint_fast64_t;

typedef long long          intmax_t;
typedef unsigned long long uintmax_t;