我不能用“长久”;我该怎么用?
答案 0 :(得分:12)
假设Snow Leopard(Mac OS X 10.6.2 - Intel),那么'long'是默认编译器的64位。
指定'g ++ -m64',它在早期版本中也可能是64位。
1 = sizeof(char)
1 = sizeof(unsigned char)
2 = sizeof(short)
2 = sizeof(unsigned short)
4 = sizeof(int)
4 = sizeof(unsigned int)
8 = sizeof(long)
8 = sizeof(unsigned long)
4 = sizeof(float)
8 = sizeof(double)
16 = sizeof(long double)
8 = sizeof(size_t)
8 = sizeof(ptrdiff_t)
8 = sizeof(time_t)
8 = sizeof(void *)
8 = sizeof(char *)
8 = sizeof(short *)
8 = sizeof(int *)
8 = sizeof(long *)
8 = sizeof(float *)
8 = sizeof(double *)
8 = sizeof(int (*)(void))
8 = sizeof(double (*)(void))
8 = sizeof(char *(*)(void))
经过测试:
i686-apple-darwin10-g++-4.2.1 (GCC) 4.2.1 (Apple Inc. build 5646) (dot 1) Copyright (C) 2007 Free Software Foundation, Inc. This is free software; see the source for copying conditions. There is NO warranty; not even for MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.
使用选项-std=c99
在Mac OS X 10.7.5上使用GCC 4.7.1进行编译,程序的输出更加广泛。感谢apalopohapa指出了long long
等原件中遗漏的疏忽。
1 = sizeof(char)
1 = sizeof(unsigned char)
2 = sizeof(short)
2 = sizeof(unsigned short)
4 = sizeof(int)
4 = sizeof(unsigned int)
8 = sizeof(long)
8 = sizeof(unsigned long)
4 = sizeof(float)
8 = sizeof(double)
16 = sizeof(long double)
8 = sizeof(size_t)
8 = sizeof(ptrdiff_t)
8 = sizeof(time_t)
8 = sizeof(long long)
8 = sizeof(unsigned long long)
8 = sizeof(uintmax_t)
1 = sizeof(int8_t)
2 = sizeof(int16_t)
4 = sizeof(int32_t)
8 = sizeof(int64_t)
1 = sizeof(int_least8_t)
2 = sizeof(int_least16_t)
4 = sizeof(int_least32_t)
8 = sizeof(int_least64_t)
1 = sizeof(int_fast8_t)
2 = sizeof(int_fast16_t)
4 = sizeof(int_fast32_t)
8 = sizeof(int_fast64_t)
8 = sizeof(uintptr_t)
8 = sizeof(void *)
8 = sizeof(char *)
8 = sizeof(short *)
8 = sizeof(int *)
8 = sizeof(long *)
8 = sizeof(float *)
8 = sizeof(double *)
8 = sizeof(int (*)(void))
8 = sizeof(double (*)(void))
8 = sizeof(char *(*)(void))
1 = sizeof(struct { char a; })
2 = sizeof(struct { short a; })
4 = sizeof(struct { int a; })
8 = sizeof(struct { long a; })
4 = sizeof(struct { float a; })
8 = sizeof(struct { double a; })
16 = sizeof(struct { char a; double b; })
16 = sizeof(struct { short a; double b; })
16 = sizeof(struct { long a; double b; })
4 = sizeof(struct { char a; char b; short c; })
16 = sizeof(struct { char a; char b; long c; })
4 = sizeof(struct { short a; short b; })
6 = sizeof(struct { char a[3]; char b[3]; })
8 = sizeof(struct { char a[3]; char b[3]; short c; })
16 = sizeof(struct { long double a; })
32 = sizeof(struct { char a; long double b; })
16 = sizeof(struct { char a; long long b; })
16 = sizeof(struct { char a; uintmax_t b; })
答案 1 :(得分:4)
包含<stdint.h>
或<inttypes.h>
(后者可在更多编译器上找到,但两者均由Apple编译器提供),并使用uint64_t
和int64_t
。它们在32位和64位目标上都是64位。