На Mac OS X в C++ на 64-разрядном ЦП, там тип, который составляет 64 бита?

Предполагая, что Snow Leopard (Mac OS X 10.6.2 - Intel), тогда long будет 64-битным с компилятором по умолчанию.

Укажите 'g ++ -m64', и в более ранних версиях он, скорее всего, будет 64-битным.

 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))

Протестировано с помощью:

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.

Компиляция с GCC 4.7.1 в Mac OS X 10.7.5 с опцией -std = c99 , выходные данные программы более обширны. Благодарю апалопохапа за указание на упущение, которое долгое время и т.д. отсутствовало в оригинале.

 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; })