value::operator=

`value::operator=`

Assignment.

Synopsis

value&
operator=(
    value const& other); (1)

value&
operator=(
    value&& other); (2)

value&
operator=(
    std::initializer_list< value_ref > init); (3)

value&
operator=(
    std::nullptr_t) noexcept; (4)

value&
operator=(
    bool b) noexcept; (5)

value&
operator=(
    signed char i) noexcept; (6)

value&
operator=(
    short i) noexcept; (7)

value&
operator=(
    int i) noexcept; (8)

value&
operator=(
    long i) noexcept; (9)

value&
operator=(
    long long i) noexcept; (10)

value&
operator=(
    unsigned char u) noexcept; (11)

value&
operator=(
    unsigned short u) noexcept; (12)

value&
operator=(
    unsigned int u) noexcept; (13)

value&
operator=(
    unsigned long u) noexcept; (14)

value&
operator=(
    unsigned long long u) noexcept; (15)

value&
operator=(
    double d) noexcept; (16)

value&
operator=(
    string_view s); (17)

value&
operator=(
    char const* s); (18)

value&
operator=(
    string const& s); (19)

value&
operator=(
    string&& s); (20)

value&
operator=(
    array const& arr); (21)

value&
operator=(
    array&& arr); (22)

value&
operator=(
    object const& obj); (23)

value&
operator=(
    object&& obj); (24)

Description

Replaces the contents of this value.

(1) replaces with an element-wise copy of the contents of other.
(2) replaces with the contents other using move semantics (see below).
(3) replaces with the value formed by constructing from init and this->storage() (see Initializer Lists).
(4) replaces with null.
(5) replaces with the boolean value b.
(6)–(10) replaces with the signed integer i.
(11)–(15) replaces with the unsigned integer u.
(16) replaces with the number d.
(17), (19) replaces with a copy of the string s.
(18), equivalent to *this = string_view(s).
(20) replaces with the string s using move semantics see below.
(21) replaces with a copy of the array arr.
(22) replaces with the array arr using move semantics (see below).
(23) replaces with a copy of the object obj.
(24) replaces with the object obj using move semantics (see below).

Move assignment for value never changes the associated memory resource. Because of this if the memory resource of the assigned value differs from that of *this, the operation is equivalent to a copy. Otherwise, it replaces the underlying storage in constant time without the possibility of exceptions.

Complexity

(1) linear in the sizes of *this and other.
(2) constant if *this->storage() == *other.storage(), otherwise linear in the sizes of *this and other.
(3) linear in the sizes of *this and init.
(4)–(16) linear in the size of *this.
(17), (19) linear in the size of *this and s.size().
(18) linear in the size of *this and std::strlen(s).
(22) constant if *this->storage() == *s.storage(), otherwise linear in the size of *this and s.size().
(21) linear in the size of *this and arr.size().
(22) constant if *this->storage() == *arr.storage(), otherwise linear in the size of *this and arr.size().
(23) linear in the size of *this and obj.size().
(24) constant if *this->storage() == *obj.storage(), otherwise linear in the size of *this and obj.size().

The size of *this is either the size of the underlying container (if there is one), or can be considered to be 1.

Exception Safety

(1)–(3), (17)–(24) strong guarantee.
(4)–(16) no-throw guarantee.

Calls to memory_resource::allocate may throw.

Parameters

Name Description

Name	Description
`other`	The source value.
`init`	The initializer list to assign from.
`b`	The new value.
`i`	The new value.
`u`	The new value.
`d`	The new value.
`s`	The new string.
`arr`	The new array.
`obj`	The new object.

other

The source value.

init

The initializer list to assign from.

b

The new value.

i

The new value.

u

The new value.

d

The new value.

s

The new string.

arr

The new array.

obj

The new object.

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