initOnce function

gistfile1.d

import std.stdio;

void initOnce(alias var)(lazy typeof(var) init)
{
	static bool hasInitialised = false;
	
	if(!hasInitialised)
	{
		var = init();
		hasInitialised = true;
	}
}

void test()
{
	static Object o;

	writeln(cast(void*)o);

	initOnce!o(new Object);
}

void main()
{
	foreach(i; 0 .. 3)
		test(); // printed null, 472FD0 and 472FD0
}