Constant expressions implementation (Using the GNU Compiler Collection (GCC))

### 4.7 Constant expressions ¶

- Whether or not an expression not explicitly sanctioned by this document is an extended constant expression, whether or not such extended constant expressions can be used in the same contexts as this document, and whether or not such extended constant expressions can affect potentially detectable semantic changes in the program (C23 6.6).

  The only extended constant expressions are those using other GNU extensions to the C language. Such extended constant expressions include integer constant expressions and arithmetic constant expressions.