Define constant variables in C++ header

Question

A program I am working on has many constants that apply throughout all classes. I want to make one header file \"Constants.h\", and be able to declare all the relevant const

Answer 1

I like the namespace better for this kind of purpose.

Option 1 :

#ifndef MYLIB_CONSTANTS_H
#define MYLIB_CONSTANTS_H

//  File Name : LibConstants.hpp    Purpose : Global Constants for Lib Utils
namespace LibConstants
{
  const int CurlTimeOut = 0xFF;     // Just some example
  ...
}
#endif

// source.cpp
#include 
int value = LibConstants::CurlTimeOut;

Option 2 :

#ifndef MYLIB_CONSTANTS_H
#define MYLIB_CONSTANTS_H
//  File Name : LibConstants.hpp    Purpose : Global Constants for Lib Utils
namespace CurlConstants
{
  const int CurlTimeOut = 0xFF;     // Just some example
  ...
}

namespace MySQLConstants
{
  const int DBPoolSize = 0xFF;      // Just some example
  ...
}
#endif



// source.cpp
#include 
int value = CurlConstants::CurlTimeOut;
int val2  = MySQLConstants::DBPoolSize;

And I would never use a Class to hold this type of HardCoded Const variables.