6.3.1.1p2 的含义，要点 2
Meaning of 6.3.1.1p2, bullet point 2
The following may be used in an expression wherever an int or unsigned int may be used:
An object or expression with an integer type (other than int or unsigned int) whose integer conversion rank is less than or equal to the rank of int and unsigned int.
A bit-field of type _Bool, int, signed int, or unsigned int.
第二个要点背后的意图是什么？
为什么要省略排名低于int的其他类型的整型字段？
这是否意味着我可以做例如：
printf("%d\n", (struct{ _Bool x:1; }){0}.x);
但不是：
printf("%d\n", (struct{ unsigned short x:1; }){0}.x);
大概是因为6.7.2.1p5:
A bit-field shall have a type that is a qualified or unqualified version of _Bool, signed int, unsigned int, or some other implementation-defined type. It is implementation-defined whether atomic types are permitted.
即无论如何，您不能可移植地创建其他类型的位域。
The following may be used in an expression wherever an
intorunsigned intmay be used:
An object or expression with an integer type (other than
intorunsigned int) whose integer conversion rank is less than or equal to the rank ofintandunsigned int.A bit-field of type
_Bool,int,signed int, orunsigned int.
第二个要点背后的意图是什么？
为什么要省略排名低于int的其他类型的整型字段？
这是否意味着我可以做例如：
printf("%d\n", (struct{ _Bool x:1; }){0}.x);
但不是：
printf("%d\n", (struct{ unsigned short x:1; }){0}.x);
大概是因为6.7.2.1p5:
A bit-field shall have a type that is a qualified or unqualified version of
_Bool,signed int,unsigned int, or some other implementation-defined type. It is implementation-defined whether atomic types are permitted.
即无论如何，您不能可移植地创建其他类型的位域。