cast the memory stored in a uint32_t as a float in C

Question

Having a Hex represented as a string in c
eg char* text = "0xffff"
I manage to hold the data in a uint32_t with the following function:

for (unsigned int i = 0; i < line_length && count < WORD_SIZE; i++) {
        char c[2]; //represent the digit as string
        c[0] = line[i];
        c[1] = '\0';
        if (isxdigit(c[0])) { //we've found a relevant char.
            res_out <<= 4; // shift left by 4 for the next 4 bits.
            res_out += (int32_t)strtol(c, NULL, 16); //set the last 4 bits bit to relevant value
                                                     //res_out <<= 4; // shift left by 4 for the next 4 bits.
            count += 4;
        }
    }

Now, having the 32 bits, the uint32_t sometimes represented a single-precision floating point number, and I would like to parse it as such
Using float f = (float)num of course casts the int representation to float (not the needed operation) and I have no other idea's how to tell memory it's actually a floating point number

Answer 1

Just for future references, As @melpomene suggested

uint32_t x = /* some single precision float value dumped into a uint32_t*/;
uint32_t float_placeholder = 0;
memcpy(&float_placeholder, &x, sizeof(uint32_t));

float_placeholder holds the true floating point number