C++: When should I use structs instead of classes and where are the speed differences?

Question

• When should I use a struct instead of a class? I\'m currently using classes for everything from OpenGL texture wrappers to bitmap fonts.

• Is

Answer 1

Instead of cheaping out and referring to other questions, I'll re-iterate what others have said before I add on to them.

struct and class are identical in C++, the only exception being that struct has a default access of public, and class has a default access of private. Performance and language feature support are identical.

Idiomatically, though, struct is mostly used for "dumb" classes (plain-old-data). class is used more to embody a true class.

In addition, I've also used struct for locally defined function objects, such as:

struct something
{
    something() : count(0) { }
    void operator()(int value) { std::cout << value << "-" << count++ << "\n"; }
    int count;
} doSomething;

std::vector values;

...

std::foreach(values.begin(); values.end(); doSomething);