std::error_code::operator=

 

C++

编译器支持

独立式和宿主式

语言

标准库

标准库头文件

命名要求

Feature test macros (C++20)

语言支持库

Concepts library (C++20)

诊断库

内存管理库

Metaprogramming library (C++11)

通用工具库

容器库

迭代器库

Ranges library (C++20)

算法库

字符串库

文本处理库

数值库

日期和时间库

输入/输出库

Filesystem library (C++17)

Concurrency support library (C++11)

Execution control library (C++26)

技术规范

符号索引

外部库

 

工具库

语言支持 Type support (基本类型，RTTI) Library feature-test macros (C++20) 程序工具 可变参数函数 initializer_list (C++11) is_constant_evaluated (C++20) is_within_lifetime (C++26) source_location (C++20) Coroutine support (C++20) Contract support (C++26) 三向比较 three_way_comparablethree_way_comparable_with (C++20)(C++20) strong_ordering (C++20) weak_ordering (C++20) partial_ordering (C++20) common_comparison_category (C++20) compare_three_way_result (C++20) compare_three_way (C++20) strong_order (C++20) weak_order (C++20) partial_order (C++20) compare_strong_order_fallback (C++20) compare_weak_order_fallback (C++20) compare_partial_order_fallback (C++20)   is_eqis_ltis_lteq (C++20)(C++20)(C++20)   is_neqis_gtis_gteq (C++20)(C++20)(C++20)

通用工具 函数对象 Bit manipulation (C++20) bitset hash (C++11) Relational operators (deprecated in C++20) rel_ops::operator!=rel_ops::operator>    rel_ops::operator<=rel_ops::operator>= 整数比较函数 cmp_equalcmp_lesscmp_less_than (C++20)(C++20)(C++20)   cmp_not_equalcmp_greatercmp_greater_than (C++20)(C++20)(C++20) in_range (C++20) Swap and type operations swap ranges::swap (C++20) exchange (C++14) declval (C++11) to_underlying (C++23) forward (C++11) forward_like (C++23) move (C++11) move_if_noexcept (C++11) as_const (C++17) 常用词汇类型 pair tuple (C++11) optional (C++17) any (C++17) variant (C++17) tuple_size (C++11) tuple_element (C++11) apply (C++17) make_from_tuple (C++17) expected (C++23)

 

诊断库

异常处理 exception uncaught_exceptionuncaught_exceptions (until C++20*)  (C++17) exception_ptr (C++11) make_exception_ptr (C++11) current_exception (C++11) rethrow_exception (C++11) nested_exception (C++11) throw_with_nested (C++11) rethrow_if_nested (C++11) 异常处理失败 terminate terminate_handler get_terminate (C++11) set_terminate bad_exception unexpected (until C++17*) unexpected_handler (until C++17*) get_unexpected (until C++17*) set_unexpected (until C++17*) 错误编号 错误码 errno 断言 assert

异常类别 logic_error invalid_argument domain_error length_error out_of_range runtime_error range_error overflow_error underflow_error tx_exception (TM TS) 系统错误 error_category (C++11) generic_category (C++11) system_category (C++11) error_condition (C++11) errc (C++11) error_code (C++11) system_error (C++11) Stacktrace stacktrace_entry (C++23) basic_stacktrace (C++23) 调试支持 is_debugger_present (C++26) breakpoint_if_debugging (C++26) breakpoint (C++26)

 

std::error_code

成员函数

error_code::error_code

error_code::operator=

error_code::assign

修改器

error_code::clear

观察器

error_code::value

error_code::category

error_code::default_error_condition

error_code::message

error_code::operator bool

非成员函数

operator==operator!=operator<operator<=> (until C++20)(until C++20)(C++20)

operator<<

辅助类

is_error_code_enum

hash<std::error_code>

 

template< class ErrorCodeEnum > error_code& operator=( ErrorCodeEnum e ) noexcept;	(1)	(since C++11)
error_code& operator=( const error_code& other ) = default;	(2)	(since C++11) (implicitly declared)
error_code& operator=( error_code&& other ) = default;	(3)	(since C++11) (implicitly declared)

1) 将错误码和相应的类别替换为表示错误码枚举 e 的值。

等价于 *this = make_error_code(e)，其中 make_error_code 仅通过实参依赖查找找到。

仅当 std::is_error_code_enum<ErrorCodeEnum>::value 为 true 时，此重载才参与重载决议。

2,3) 隐式定义的复制赋值运算符和移动赋值运算符将 other 的内容赋值给 *this。

参数

e	-	要构造的错误码枚举
other	-	要赋值的另一个错误码

返回值

*this

缺陷报告

以下行为变更缺陷报告被追溯应用于先前发布的 C++ 标准。

DR	应用于	发布时的行为	正确行为
LWG 3629	C++11	仅使用了 std::make_error_code 重载	使用了 ADL 找到的重载

参见

assign

赋值另一个错误码 (public member function)