transform() vs generate()!!!

[TheToaster]

What is the difference between the transform() and the generate() algorithms in the STL?

[LB]

Maybe you should try reading their descriptions?

std::transform:
http://www.cplusplus.com/reference/algorithm/transform/
http://en.cppreference.com/w/cpp/algorithm/transform

std::generate
http://www.cplusplus.com/reference/algorithm/generate/
http://en.cppreference.com/w/cpp/algorithm/generate

[TheToaster]

So the only difference is that std::transform applies the result of the operation in a different t iterator range?

What about if you use the source range the same as the destination range? Would that be equivalent to using std::generate?

[helios]

No. std::generate is the same as

for each x in xs
    x = function()

std::transform is the same as

assert(xs.size() == ys.size())
for each i in xs.indices()
    ys[i] = function(xs[i])

std::generate expects a nullary function, while std::transform expects a unary function.

PS: When I say "function" in this context, I'm really saying "function-like object".

[TheToaster]

PS: When I say "function" in this context, I'm really saying "function-like object"

I think you mean "functor" or "function object", am I correct? (or anything that can be called)

[helios]

Well, no, because a function is not a functor. You could say f is a function-like object iff f(/*...*/) compiles.