I am kind of new to C and I cannot figure out why the following code is not working:
typedef struct{
uint8_t a;
uint8_t* b;
} test_struct;
test_struct test = {
.a = 50,
.b = {62, 33}
};
If I do this instead, it works:
int temp[] = {62, 33};
test_struct test = {
.a = 50,
.b = temp
};
The b member is not an array but a pointer. So when you attempt to initialize like this:
test_struct test = {
.a = 50,
.b = {62, 33}
};
You're setting test.b to the value 62 converted to a pointer, with the extra initializer discarded.
The second case works because you're initializing the b member with temp which is an int array which decays to a pointer to an int to match the type of the member b.
You could also do something like this and it would work:
test_struct test = {
.a = 50,
.b = (int []){62, 33}
};
However, the pointer to the compound literal will only be valid in the scope it was declared. So if you defined this struct inside of a function and returned a copy of it, the pointer would no longer be valid.
.b value in the second example? Is it necessary to use a static variable?
test is declared at file scope then the compound literal has full program lifetime.
bto? A pointer to what exactly? In the second code, it's clear, it points totemp. What should the first code makebpoint to?