std:: quoted

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C++
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(C++11)
(C++11)
(C++11)
(C++11)
Quoted manipulator
quoted
(C++14)
Defined in header <iomanip>
template < class CharT >

/*unspecified*/ quoted ( const CharT * s,

CharT delim = CharT ( '"' ) , CharT escape = CharT ( ' \\ ' ) ) ;
(1) (since C++14)
template < class CharT, class Traits, class Allocator >

/*unspecified*/ quoted ( const std:: basic_string < CharT, Traits, Allocator > & s,

CharT delim = CharT ( '"' ) , CharT escape = CharT ( ' \\ ' ) ) ;
(2) (since C++14)
template < class CharT, class Traits >

/*unspecified*/ quoted ( std:: basic_string_view < CharT, Traits > s,

CharT delim = CharT ( '"' ) , CharT escape = CharT ( ' \\ ' ) ) ;
(3) (since C++17)
template < class CharT, class Traits, class Allocator >

/*unspecified*/ quoted ( std:: basic_string < CharT, Traits, Allocator > & s,

CharT delim = CharT ( '"' ) , CharT escape = CharT ( ' \\ ' ) ) ;
(4) (since C++14)

Allows insertion and extraction of quoted strings, such as the ones found in CSV or XML .

1-3) When used in an expression out << quoted ( s, delim, escape ) , where out is an output stream with char_type equal to CharT and, for overloads (2,3), traits_type equal to Traits , behaves as a FormattedOutputFunction , which inserts into out a sequence of characters seq constructed as follows:
a) First, the character delim is added to the sequence.
b) Then every character from s , except if the next character to output equals delim or equals escape (as determined by the stream's traits_type :: eq ), then first appends an extra copy of escape .
c) In the end, delim is appended to seq once more.
Then, if seq. size ( ) < out. width ( ) , adds out. width ( ) - seq. size ( ) copies of the fill character out. fill ( ) either at the end of the sequence (if ios_base :: left is set in out. flags ( ) ) or at the beginning of the sequence (in all other cases).
Finally, outputs each character from the resulting sequence as if by calling out. rdbuf ( ) - > sputn ( seq, n ) , where n = std:: max ( out. width ( ) , seq. size ( ) ) and out. width ( 0 ) to cancel the effects of std::setw , if any.
4) When used in an expression in >> quoted ( s, delim, escape ) , where in is an input stream with char_type equal to CharT and traits_type equal to Traits , extracts characters from in , using std::basic_istream::operator>> , according to the following rules:
a) If the first character extracted does not equal delim (as determined by the stream's traits_type::eq ), then simply performs in >> s .
b) Otherwise (if the first character is the delimiter):
1) Turns off the skipws flag on the input stream.
2) Empties the destination string by calling s. clear ( ) .
3) Extracts characters from in and appends them to s , except that whenever an escape character is extracted, it is ignored and the next character is appended to s . Extraction stops when ! in == true or when an unescaped delim character is found.
4) Discards the final (unescaped) delim character.
5) Restores the skipws flag on the input stream to its original value.

Parameters

s - the string to insert or extract
delim - the character to use as the delimiter, defaults to "
escape - the character to use as the escape character, defaults to \

Return value

Returns an object of unspecified type such that the described behavior takes place.

Exceptions

Throws std::ios_base::failure if operator >> or operator << throws.

Notes

Feature-test macro Value Std Feature
__cpp_lib_quoted_string_io 201304L (C++14) std::quoted

Example

Run this code 
#include <iomanip>
#include <iostream>
#include <sstream>
 
void default_delimiter()
{
    const std::string in = "std::quoted() quotes this string and embedded \"quotes\" too";
    std::stringstream ss;
    ss << std::quoted(in);
    std::string out;
    ss >> std::quoted(out);
 
    std::cout << "Default delimiter case:\n"
                 "read in     [" << in << "]\n"
                 "stored as   [" << ss.str() << "]\n"
                 "written out [" << out << "]\n\n";
}
 
void custom_delimiter()
{
    const char delim{'$'};
    const char escape{'%'};
 
    const std::string in = "std::quoted() quotes this string and embedded $quotes$ $too";
    std::stringstream ss;
    ss << std::quoted(in, delim, escape);
    std::string out;
    ss >> std::quoted(out, delim, escape);
 
    std::cout << "Custom delimiter case:\n"
                 "read in     [" << in << "]\n"
                 "stored as   [" << ss.str() << "]\n"
                 "written out [" << out << "]\n\n";
}
 
int main()
{
    default_delimiter();
    custom_delimiter();
}

Output: 

Default delimiter case:
read in     [std::quoted() quotes this string and embedded "quotes" too]
stored as   ["std::quoted() quotes this string and embedded \"quotes\" too"]
written out [std::quoted() quotes this string and embedded "quotes" too]
 
Custom delimiter case:
read in     [std::quoted() quotes this string and embedded $quotes$ $too]
stored as   [$std::quoted() quotes this string and embedded %$quotes%$ %$too$]
written out [std::quoted() quotes this string and embedded $quotes$ $too]

See also

(C++20)
stores formatted representation of the arguments in a new string
(function template)
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