_Generic
_Generic is a C11 primary expression that selects one expression from type-associated alternatives according to the type of a controlling expression.
Modern C, Third Edition
A generic selection is a C11 expression construct that selects one expression from a set based on the type of a controlling expression.
- How it is used
- Provides compile-time type-based selection for interfaces such as type-generic macros.
- How deep it goes
- Defines the expression form and works through function dispatch, then introduces two-argument selection and its conversion concerns.
- Examples
- Uses a `fabs` dispatch macro and a two-argument `min` interface; proposes extensions to complex and integer types.
- What you can do after
- Apply it via `_Generic` to dispatch a macro to functions selected by argument type.
Modern C
_Generic is a C11 primary expression that selects one expression from type-associated alternatives based on the type of a controlling expression.
- How it is used
- Uses type-based selection to build function-like macro interfaces such as generic absolute value, minimum, and tracing utilities.
- How deep it goes
- Defines syntax and dispatches complete macro examples, then stops short of broader macro-programming complications.
- Examples
- Demonstrates fabs dispatch, floating-point minimum, maximum-value selection, and tracing format or value conversion.
- What you can do after
- Apply _Generic through macros to select type-specific functions, expressions, format strings, or conversions.
Related concepts
- type-generic macroused by · A type-generic macro is a macro-based interface whose expansion selects or adapts operations according to the types of its arguments or associated objects.
- type-generic interfaceimplements · A type-generic interface is a programming interface that selects or adapts operations according to the types of its arguments or associated values.
- function-like macroused by · A function-like macro is a macro invoked with function-like syntax that accepts token input and expands or transforms it into generated source.
- inline functionuses · An inline function is a function defined or designated for incorporation at its use site, either syntactically or through compiler substitution, rather than necessarily invoked through an ordinary call.
- type traituses · A type trait is a compile-time facility that queries or transforms a type and produces a result representing the requested property or type.
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