4 ms·

I don't see how type aliasing negates anything of what I am saying. Types are an abstraction but C++ allows you to extract its pointer, to make a sizeof() of it

by Iv 9y ago

I don't see how type aliasing negates anything of what I am saying. Types are an abstraction but C++ allows you to extract its pointer, to make a sizeof() of it, to do pointer casting and arithmetics. You can go low level with most high level languages, what sets C++ apart is that using low-level instructions have generally zero overhead. ptr2 = static_cast<uint8_t*>(ptr)+5; pretty much maps to the assembly code you would expect.

pcwalton 9y ago
> Types are an abstraction but C++ allows you to extract its pointer, to make a sizeof() of it, to do pointer casting and arithmetics. And the semantics of those operations are dictated not by what the underlying machine does but what the C++ abstract machine does, which is very different. The underlying memory is still typed. > You can go low level with most high level languages, what sets C++ apart is that using low-level instructions have generally zero overhead. That's true for the JVM, .NET, even JS... > ptr2 = static_cast<uint8_t*>(ptr)+5; pretty much maps to the assembly code you would expect. No, it doesn't, not after optimizations and undefined behavior. It's perfectly acceptable for the compiler to turn that into a no-op if, for example, "ptr" was a null pointer.