8 Statements [stmt.stmt]

8.5 Selection statements [stmt.select]

8.5.1 General [stmt.select.general]

Selection statements choose one of several flows of control.
selection-statement:
if constexpr ( init-statement condition ) statement
if constexpr ( init-statement condition ) statement else statement
if ! consteval compound-statement
if ! consteval compound-statement else statement
switch ( init-statement condition ) statement
See [dcl.meaning] for the optional attribute-specifier-seq in a condition.
[Note 1: 
An init-statement ends with a semicolon.
— end note]
[Note 2: 
Each selection-statement and each substatement of a selection-statement has a block scope ([basic.scope.block]).
— end note]