---
name: "std::__detector"
section: "3cxx"
platform: "linux"
package: "libstdc++-10-doc"
version: "10.2.1-6"
release: "Debian 11 (Bullseye)"
platforms: ["linux"]
url: "https://new.carta.tech/std::__detector"
---

# std::\_\_detector(3cxx)

Implementation of the detection idiom (negative case).

## NAME

std::\_\_detector\< \_Default, \_AlwaysVoid, \_Op, \_Args \> - Implementation of the detection idiom (negative case).

## SYNOPSIS

### Public Types

using **type** = \_Default\
 using **value\_t** = **false\_type**\

## Detailed Description

### template\<typename \_Default, typename \_AlwaysVoid, template\< typename... \> class \_Op, typename... \_Args\>

struct std::\_\_detector\< \_Default, \_AlwaysVoid, \_Op, \_Args \>" Implementation of the detection idiom (negative case).

Definition at line 2582 of file type\_traits.

## Author

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