There is an unwanted behaviour when using an invariant storage class within a struct/class.

------------------------------------------------------------------------
import std.stdio;

struct MyStruct
{
    int x = 1;
    invariant int y = 2;

    //void resety() { y = 3; }; //error: constant y is not an lvalue - as expected

    /*
    	alternatives, that work as expected:
    	const int y = 2;
    	static invariant int y = 2;

    	final int y = 2; //but this takes up storage for each instance
    */
}

void main() {
	MyStruct mystruct;
	mystruct.x = 1; //ok
	//mystruct.y == 1, expected: 2
	//mystruct.y = 2; //no error, but mystruct.x also becomes 2
	writefln("mystruct.sizeof: %s mystruct.x: %s mystruct.y: %s", mystruct.sizeof, mystruct.x, mystruct.y);
}