Difference between revisions of "cpp/string/basic string/insert"

Revision as of 21:10, 2 October 2021

(1)

basic_string& insert( size_type index, size_type count, CharT ch );

(until C++20)

constexpr basic_string& insert( size_type index, size_type count, CharT ch );

(since C++20)

(2)

basic_string& insert( size_type index, const CharT* s );

(until C++20)

constexpr basic_string& insert( size_type index, const CharT* s );

(since C++20)

(3)

basic_string& insert( size_type index, const CharT* s, size_type count );

(until C++20)

constexpr basic_string& insert( size_type index,
const CharT* s, size_type count );

(since C++20)

(4)

basic_string& insert( size_type index, const basic_string& str );

(until C++20)

constexpr basic_string& insert( size_type index, const basic_string& str );

(since C++20)

(5)

basic_string& insert( size_type index, const basic_string& str,
size_type index_str, size_type count );

(until C++14)

basic_string& insert( size_type index, const basic_string& str,
size_type index_str, size_type count = npos );

(since C++14)
(until C++20)

constexpr basic_string& insert( size_type index, const basic_string& str,
size_type index_str, size_type count = npos );

(since C++20)

(6)

iterator insert( iterator pos, CharT ch );

(until C++11)

iterator insert( const_iterator pos, CharT ch );

(since C++11)
(until C++20)

constexpr iterator insert( const_iterator pos, CharT ch );

(since C++20)

(7)

void insert( iterator pos, size_type count, CharT ch );

(until C++11)

iterator insert( const_iterator pos, size_type count, CharT ch );

(since C++11)
(until C++20)

constexpr iterator insert( const_iterator pos, size_type count, CharT ch );

(since C++20)

(8)

template< class InputIt >
void insert( iterator pos, InputIt first, InputIt last );

(until C++11)

template< class InputIt >
iterator insert( const_iterator pos, InputIt first, InputIt last );

(since C++11)
(until C++20)

template< class InputIt >
constexpr iterator insert( const_iterator pos, InputIt first, InputIt last );

(since C++20)

(9)

iterator insert( const_iterator pos, std::initializer_list<CharT> ilist );

(since C++11)
(until C++20)

constexpr iterator insert( const_iterator pos,
std::initializer_list<CharT> ilist );

(since C++20)

(10)

template< class T >
basic_string& insert( size_type pos, const T& t );

(since C++17)
(until C++20)

template< class T >
constexpr basic_string& insert( size_type pos, const T& t );

(since C++20)

(11)

template< class T >

basic_string& insert( size_type index, const T& t,

size_type index_str, size_type count = npos );

(since C++17)
(until C++20)

template< class T >

constexpr basic_string& insert( size_type index, const T& t,

size_type index_str, size_type count = npos );

(since C++20)

Inserts characters into the string.

1) Inserts count copies of character ch at the position index

2) Inserts null-terminated character string pointed to by s at the position index. The length of the string is determined by the first null character using Traits::length(s).

3) Inserts the characters in the range [s, s+count) at the position index. The range can contain null characters.

4) Inserts string str at the position index

5) Inserts a string, obtained by str.substr(index_str, count) at the position index

6) Inserts character ch before the character pointed by pos

7) Inserts count copies of character ch before the element (if any) pointed by pos

8) Inserts characters from the range [first, last) before the element (if any) pointed by pos. This overload does not participate in overload resolution if InputIt does not satisfy LegacyInputIterator.(since C++11)

9) Inserts elements from initializer list ilist before the element (if any) pointed by pos

10) Implicitly converts t to a string view sv as if by std::basic_string_view<CharT, Traits> sv = t;, then inserts the elements from sv before the element (if any) pointed by pos, as if by insert(pos, sv.data(), sv.size()).

This overload participates in overload resolution only if std::is_convertible_v<const StringViewLike&,
std::basic_string_view<CharT, Traits>> is true and std::is_convertible_v<const StringViewLike&, const CharT*> is false.

11) Implicitly converts t to a string view sv as if by std::basic_string_view<CharT, Traits> sv = t;, then inserts, before the element (if any) pointed by pos, the characters from the subview [index_str, index_str+count) of sv. If the requested subview lasts past the end of sv, or if count == npos, the resulting subview is [index_str, sv.size()). If index_str > sv.size(), or if index > size(), std::out_of_range is thrown.

This overload participates in overload resolution only if std::is_convertible_v<const StringViewLike&,
std::basic_string_view<CharT, Traits>> is true and std::is_convertible_v<const StringViewLike&, const CharT*> is false.

index	-	position at which the content will be inserted
pos	-	iterator before which the characters will be inserted
ch	-	character to insert
count	-	number of characters to insert
s	-	pointer to the character string to insert
str	-	string to insert
first, last	-	range defining characters to insert
index_str	-	position of the first character in the string `str` to insert
ilist	-	std::initializer_list to insert the characters from
t	-	object (convertible to std::basic_string_view) to insert the characters from
Type requirements
- `InputIt` must meet the requirements of LegacyInputIterator.

Return value

1-5,10-11) *this

6-9) An iterator which refers to the copy of the first inserted character or pos if no characters were inserted (count==0 or first==last or ilist.size()==0)

Exceptions

1-4, 10) std::out_of_range if index > size()

5) Throws std::out_of_range if index > size() or if index_str > str.size().

11) Throws std::out_of_range if index > size() or if index_str > sv.size().

In all cases, throws std::length_error if size() + ins_count > max_size() where ins_count is the number of characters that will be inserted and may throw any exceptions thrown by Allocator::allocate.

In any case, if an exception is thrown for any reason, this function has no effect (strong exception guarantee).

(since C++11)

Example

Run this code

#include <cassert>
#include <iterator>
#include <string>
using namespace std::string_literals;
int main()
{
    std::string s = "xmplr";
 
    // insert(size_type index, size_type count, char ch)
    s.insert(0, 1, 'E');
    assert("Exmplr" == s);
 
    // insert(size_type index, const char* s)
    s.insert(2, "e");
    assert("Exemplr" == s);
 
    // insert(size_type index, string const& str)
    s.insert(6, "a"s);
    assert("Exemplar" == s);
 
    // insert(size_type index, string const& str,
    //     size_type index_str, size_type count)
    s.insert(8, " is an example string."s, 0, 14);
    assert("Exemplar is an example" == s);
 
    // insert(const_iterator pos, char ch)
    s.insert(s.cbegin() + s.find_first_of('n') + 1, ':');
    assert("Exemplar is an: example" == s);
 
    // insert(const_iterator pos, size_type count, char ch)
    s.insert(s.cbegin() + s.find_first_of(':') + 1, 2, '=');
    assert("Exemplar is an:== example" == s);
 
    // insert(const_iterator pos, InputIt first, InputIt last)
    {
        std::string seq = " string";
        s.insert(s.begin() + s.find_last_of('e') + 1,
            std::begin(seq), std::end(seq));
        assert("Exemplar is an:== example string" == s);
    }
 
    // insert(const_iterator pos, std::initializer_list<char>)
    s.insert(s.cbegin() + s.find_first_of('g') + 1, { '.' });
    assert("Exemplar is an:== example string." == s);
}

Defect reports

The following behavior-changing defect reports were applied retroactively to previously published C++ standards.

DR	Applied to	Behavior as published	Correct behavior
LWG 2946	C++17	`string_view` overload causes ambiguity in some cases	avoided by making it a template

Compiler support
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Language
Standard library
Standard library headers
Named requirements
Feature test macros (C++20)
Language support library
Concepts library (C++20)
Metaprogramming library (C++11)
Diagnostics library
General utilities library
Strings library
Containers library
Iterators library
Ranges library (C++20)
Algorithms library
Numerics library
Localizations library
Input/output library
Filesystem library (C++17)
Regular expressions library (C++11)
Concurrency support library (C++11)
Execution support library (C++26)
Technical specifications
Symbols index
External libraries

Null-terminated strings
Byte strings
Multibyte strings
Wide strings
Classes
basic_string
basic_string_view (C++17)
char_traits

append	appends characters to the end (public member function) [edit]
push_back	appends a character to the end (public member function) [edit]

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Difference between revisions of "cpp/string/basic string/insert"

Revision as of 21:10, 2 October 2021

Contents

Parameters

Return value

Exceptions

Example

Defect reports

See also

Navigation

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@@ Line 4: / Line 4: @@
 {{dcl rev multi | num=1
 | dcl1=
-basic_string& insert( size_type index,
+basic_string& insert( size_type index, size_type count, CharT ch );
-                      size_type count,
-                      CharT ch );
 | since2=c++20 |dcl2=
-constexpr basic_string& insert( size_type index,
+constexpr basic_string& insert( size_type index, size_type count, CharT ch );
-                                size_type count,
-                                CharT ch );
 }}
 {{dcl rev multi | num=2
 | dcl1=
-basic_string& insert( size_type index,
+basic_string& insert( size_type index, const CharT* s );
-                      const CharT* s );
 | since2=c++20 | dcl2=
-constexpr basic_string& insert( size_type index,
+constexpr basic_string& insert( size_type index, const CharT* s );
-                                const CharT* s );
 }}
 {{dcl rev multi | num=3
 | dcl1=
-basic_string& insert( size_type index,
+basic_string& insert( size_type index, const CharT* s, size_type count );
-                      const CharT* s,
-                      size_type count );
 | since2=c++20 | dcl2=
 constexpr basic_string& insert( size_type index,
-                                 const CharT* s,
+                                 const CharT* s, size_type count );
-                                size_type count );
 }}
 {{dcl rev multi | num=4
 | dcl1=
-basic_string& insert( size_type index,
+basic_string& insert( size_type index, const basic_string& str );
-                      const basic_string& str );
 | since2=c++20 | dcl2=
-constexpr basic_string& insert( size_type index,
+constexpr basic_string& insert( size_type index, const basic_string& str );
-                                const basic_string& str );
 }}
 {{dcl rev multi | num=5
 | dcl1=
-basic_string& insert( size_type index,
+basic_string& insert( size_type index, const basic_string& str,
-                      const basic_string& str,
+                       size_type index_str, size_type count );
-                       size_type index_str,
-                      size_type count );
 | since2=c++14 | dcl2=
-basic_string& insert( size_type index,
+basic_string& insert( size_type index, const basic_string& str,
-                      const basic_string& str,
+                       size_type index_str, size_type count = npos );
-                       size_type index_str,
-                      size_type count = npos);
 | since3=c++20 | dcl3=
-constexpr basic_string& insert( size_type index,
+constexpr basic_string& insert( size_type index, const basic_string& str,
-                                const basic_string& str,
+                                 size_type index_str, size_type count = npos );
-                                 size_type index_str,
-                                size_type count = npos);
 }}
 {{dcl rev multi | num=6
 | dcl1=
-iterator insert( iterator pos,
+iterator insert( iterator pos, CharT ch );
-                 CharT ch );
 | since2=c++11 | dcl2=
-iterator insert( const_iterator pos,
+iterator insert( const_iterator pos, CharT ch );
-                 CharT ch );
 | since3=c++20 | dcl3=
-constexpr iterator insert( const_iterator pos,
+constexpr iterator insert( const_iterator pos, CharT ch );
-                           CharT ch );
 }}
 {{dcl rev multi | num=7
 | dcl1=
-void insert( iterator pos,
+void insert( iterator pos, size_type count, CharT ch );
-             size_type count,
-             CharT ch );
 | since2=c++11 | dcl2=
-iterator insert( const_iterator pos,
+iterator insert( const_iterator pos, size_type count, CharT ch );
-                 size_type count,
-                 CharT ch );
 | since3=c++20 | dcl3=
-constexpr iterator insert( const_iterator pos,
+constexpr iterator insert( const_iterator pos, size_type count, CharT ch );
-                           size_type count,
-                           CharT ch );
 }}
 {{dcl rev multi | num=8
 | dcl1=
 template< class InputIt >
-void insert( iterator pos,
+void insert( iterator pos, InputIt first, InputIt last );
-             InputIt first,
-             InputIt last );
 | since2=c++11 | dcl2=
 template< class InputIt >
-iterator insert( const_iterator pos,
+iterator insert( const_iterator pos, InputIt first, InputIt last );
-                 InputIt first,
-                 InputIt last );
 | since3=c++20 | dcl3=
 template< class InputIt >
-constexpr iterator insert( const_iterator pos,
+constexpr iterator insert( const_iterator pos, InputIt first, InputIt last );
-                           InputIt first,
-                           InputIt last );
 }}
 {{dcl rev multi | num=9
 | since1=c++11 | dcl1=
-iterator insert( const_iterator pos,
+iterator insert( const_iterator pos, std::initializer_list<CharT> ilist );
-                 std::initializer_list<CharT> ilist );
 | since2=c++20 | dcl2=
 constexpr iterator insert( const_iterator pos,
@@ Line 108: / Line 75: @@
 | since1=c++17 | dcl1=
 template< class T >
-basic_string& insert( size_type pos,
+basic_string& insert( size_type pos, const T& t );
-                      const T& t );
 | since2=c++20 | dcl2=
 template< class T >
-constexpr basic_string& insert( size_type pos,
+constexpr basic_string& insert( size_type pos, const T& t );
-                                const T& t );
 }}
 {{dcl rev multi | num=11
 | since1=c++17 | dcl1=
 template< class T >
-basic_string& insert( size_type index,
+basic_string& insert( size_type index, const T& t,
-                      const T& t,
+                       size_type index_str, size_type count = npos );
-                       size_type index_str,
-                      size_type count = npos );
 | since2=c++20 | dcl2=
 template< class T >
-constexpr basic_string& insert( size_type index,
+constexpr basic_string& insert( size_type index, const T& t,
-                                const T& t,
+                                 size_type index_str, size_type count = npos );
-                                 size_type index_str,
-                                size_type count = npos );
 }}
 {{dcl end}}