Runtime Static Initialization Order Idioms

Intent

Control the order of initialization and destruction of non-local static objects across compilation units that are otherwise ordered in an implementation dependent manner.

Motivation

• Order of initialization of static objects spread across different compilation units is not well defined. Order of destruction is the reverse of initialization order but initialization order itself is implementation defined. Bring order to this chaos.
• The destructor of static objects are non-trivial and have important side-effects that have to happen

Solution and Sample Code

The following idioms are commonly used to control the order of initialization of static objects.

• Construct On First Use
• Nifty Counter Idiom (a.k.a. Schwarz Counter Idiom)