Reinterpret cast in C - cannot take the address of an rvalue

I have two structs struct A and struct B with the same memory layout, and I want to cast a return value of type struct A to type struct B, for example, in C++, I can achieve this goal in single line (without any temporary variable) like this:

#include <utility>
struct Temp {
    int a;
    int b;
};
struct MyTemp {
    int a;
    int b;
};
struct Temp get_temp(int a, int b) {
    struct Temp temp = {
        .a = a,
        .b = b,
    };
    return temp;
}
int main() {
    struct MyTemp mt = reinterpret_cast<MyTemp &&>(std::move(get_temp(1, 2)));
}

However, I can’t find an equivalent in C, foe example, the following code in C does not compile:

void *test = &test;
struct Temp {
    int a;
    int b;
};
struct MyTemp {
    int a;
    int b;
};
struct Temp get_temp(int a, int b) {
    struct Temp temp = {
        .a = a,
        .b = b,
    };
    return temp;
}
int main() {
    struct MyTemp mt = *(struct MyTemp *)&get_temp(1, 2);
    // error: cannot take the address of an rvalue of type 'struct Temp'
}

So my question is, is there any way to do the same thing I did in C++? If there’s not, why? And why can std::move bypass this trouble?

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