How to pass values during compilation with g++ using -DN flag

compiler-flags, g++, gcc

Solution

`-DXXX` flag is just like adding `#define XXX`. So `-DN=2` is just like `#define N 2`.

And you can pass values during compilation using this flag.

Reference:

- GCC Preprocessor Options

Problem

I've heard that you can set values in your c++ program during compilation using g++'s -DN flag. Can anybody explain how? Thank you

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