---
name: "std::unary_function"
section: "3cxx"
platform: "linux"
package: "libstdc++-12-doc"
version: "12.4.0-5"
release: "Debian 13 (Trixie)"
platforms: ["linux"]
url: "https://new.carta.tech/std::unary_function/3cxx"
---

# std::unary\_function(3cxx)

## NAME

std::unary\_function\< \_Arg, \_Result \>

## SYNOPSIS

`#include <functional>`

Inherited by std::\_Identity\< \_Value \>, std::\_Select1st\< pair\< const \_Key, \_Tp \> \>, and **std::pointer\_to\_unary\_function\< \_Arg, \_Result \>**.

### Public Types

**typedef** \_Arg **argument\_type**\
 `argument_type` is the type of the argument  **typedef** \_Result **result\_type**\
 `result_type` is the return type

## Detailed Description

### template\<typename \_Arg, typename \_Result\>

struct std::unary\_function\< \_Arg, \_Result \>"Helper for defining adaptable unary function objects.

**Deprecated**

Deprecated in C++11, no longer in the standard since C++17.

## Member Typedef Documentation

### template\<typename \_Arg , typename \_Result \> typedef \_Arg std::unary\_function\< \_Arg, \_Result \>::argument\_type

`argument_type` is the type of the argument

### template\<typename \_Arg , typename \_Result \> typedef \_Result std::unary\_function\< \_Arg, \_Result \>::result\_type

`result_type` is the return type

## Author

Generated automatically by Doxygen for libstdc++ from the source code.