Question

What does this macro do? I am not able to understand its definition:

#define PAIR(def) [def] = { .name = #def, .val = def, },

From : ltp-full-20120401/lib/tst_res.c line 183

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Answer 1

It looks like it is used to initialize an array of structs.

#define PAIR(def) [def] = { .name = #def, .val = def, },

the macro used as follows PAIR(FOOBAR) would expand to:

[FOOBAR] = { .name = "FOOBAR", .val = FOOBAR, },

.name and .val would be members of the struct type of the array elements.