C 结构初始化 : strange way

Question

在阅读我遇到的代码时，结构的以下定义和初始化:

// header file
struct foo{
char* name;
int value;
};

//Implementation file
struct foo fooElmnt __foo;
// some code using fooElmnt
struct foo fooElmnt __foo = {
    .name = "NAME";
    .value = some_value;
}

这在 C 中意味着什么，它与通常的声明有何不同？

Answer 1

它叫做 designated initialization ,

In a structure initializer, specify the name of a field to initialize with .fieldname = before the element value. For example, given the following structure,

 struct point { int x, y; };

the following initialization

 struct point p = { .y = yvalue, .x = xvalue };

is equivalent to

 struct point p = { xvalue, yvalue };

如果您继续阅读，它会解释 .fieldname 被称为 designator .

更新:我不是 C99 专家，但我无法编译代码。这是我必须做出的改变:

// header file
struct foo{
char* name;
int value;
};

//Implementation file
//struct foo fooElmnt __foo;
// some code using fooElmnt
struct foo fooElmnt  = {
    .name = "NAME",
    .value = 123
};

你能编译它吗？我用了TCC .