DebugValue

A Wrapper type for values that are only needed with debug assertions.

lib.rs:

A DebugValue<T> is a T that is only present if debug assertions are enabled. On debug builds it has the exact same layout as T. On release builds it is a zero-sized-type.

 # use debug_value::DebugValue;
 # fn f(s:&mut String){}
 let mut x = String::from("Mutated but restored by f");
 let passed_in = DebugValue::new_cloned(&x);
 f(&mut x);
 passed_in.assert_eq(&x);