CODEWITHSUNDEEP
c++c++11
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Reputation: 2793

fastest way to assign range of integers from 0 to x to a container

x is an unsigned integer. Runtime-wise, what's the fastest and most elegant way to declare a container/initializer list filled with unsigned integers from 0 to x?

Ideally I'd like the solution to be a one-liner, something along the line of:

std::vector<int> v = {0..x};

This is what I have so far, but I'm not sure about the performance:

std::vector<int> v(x);
std::generate_n(v.begin(), x, [] { static int i = -1; ++i; return i;});

Upvotes: 3

Views: 102

Answers (1)

Markus Mayr
Markus Mayr

Reputation: 4118

Since C++11, there is a function in the C++ standard library that is made specifically for this: std::iota

Upvotes: 4

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