Deruago/OldVal

OldVal allows you to re-use the initial value of some object with minimal syntactic boilerplate. This allows you to avoid Temporaries, which can make code cleaner.

OldVal

Reuse old values with little syntactic boilerplate.

Examples

Re-use integer values

Using OldVal:

#include <OldVal.h>
#include <iostream>

using OldInt = Old<int>;

void Update(OldInt a, OldInt b, OldInt c)
{
    a = b + 1;
    b = a + 1;
    c = a + 2;
}

int main()
{
	int a = 2;
	int b = 0;
	int c = 0;
	Update(a, b, c);
	
	// Output: 1 3 4
	std::cout << a << " " << b << " " << c << "\n"; 

	return 0;
}

Alternative using Temporaries:

#include <iostream>

void Update(int& a, int& b, int& c)
{
	int newA = b + 1;
	int newB = a + 1;
	int newC = a + 2;
	a = newA;
	b = newB;
	c = newC;
}

int main()
{
	int a = 2;
	int b = 0;
	int c = 0;
	Update(a, b, c);
	
	// Output: 1 3 4
	std::cout << a << " " << b << " " << c << "\n"; 

	return 0;
}