Reading bytes and converting to int

[joao]

Hello everyone, I recently discovered the D language.
So, I want to open a file a read 4 bytes and get the int value.
string bytes = f.read(4)

I tried to cast but give me message it was deprecated.

uint value = cast (uint) bytes

If bytes was for example, "\x24\x00\x00\x00" I would like to 
value to be 0x24.
I know how to do this in Python, it is done with struct.unpack.
Thanks.