Namespaces
Variants
Actions

std::execution::just_error

From cppreference.com
< cpp‎ | execution
 
C++
 
Execution control library
Defined in header <execution>
inline constexpr just_error_t just_error{};
struct just_error_t { /*unspecified*/ };
(since C++26)
(customization point object)
Call signature
execution::sender auto just_error( auto&& error );
(since C++26)

A sender factory that returns a sender which completes immediately by calling the receiver’s set_error().

Let e be a subexpression represented by an input error which will be injected and returned by the receiver. The expression just_error(e) is expression-equivalent to /*make-sender*/(just_error, /*product-type*/(e))

Customization point objects

The name execution::just_error denotes a customization point object, which is a const function object of a literal semiregular class type. The cv-unqualified version of its type is a tag type denoted as execution::just_error_t. See CustomizationPointObject for details.

[edit] Notes

If the provided error is an lvalue reference, a copy is made inside the returned sender and a non-const lvalue reference to the copy is sent to the receiver’s set_error. If the provided value is an rvalue reference, it is moved into the returned sender and an rvalue reference to it is sent to the receiver’s set_error.

[edit] Example

Follow Lee on X/Twitter - Father, Husband, Serial builder creating AI, crypto, games & web tools. We are friends :) AI Will Come To Life!

Check out: eBank.nz (Art Generator) | Netwrck.com (AI Tools) | Text-Generator.io (AI API) | BitBank.nz (Crypto AI) | ReadingTime (Kids Reading) | RewordGame | BigMultiplayerChess | WebFiddle | How.nz | Helix AI Assistant