|
+
+ Quoted String
+ |
+
C++ Standard library stream I/O for strings that contain embedded spaces +can produce unexpected results. For example,
+++std::stringstream ss; +std::string original = "fooled you"; +std::string round_trip; + +ss << original; +ss >> round_trip; + +std::cout << original; // outputs: fooled you +std::cout << round_trip; // outputs: fooled + +assert(original == round_trip); // assert will fire+
The Boost quoted string stream I/O manipulator places delimiters, defaulted
+to the double-quote ("), around strings on output, and strips off
+the delimiters on input. This ensures strings with embedded spaces round-trip as
+desired. For example,
++std::stringstream ss; +std::string original = "fooled you"; +std::string round_trip; + +ss << quoted(original); +ss >> quoted(round_trip); + +std::cout << quoted(original); // outputs: "fooled you" +std::cout << round_trip; // outputs: fooled you + +assert(original == round_trip); // assert will not fire+
namespace boost
+{
+ namespace io
+ {
+ // manipulator for const std::basic_string&
+
+ template <class Char, class Traits, class Alloc>
+ unspecified-type1 quoted(const std::basic_string<Char, Traits, Alloc>& string, Char escape='\\', Char delim='\"');
+
+ // manipulator for const C-string*
+
+ template <class Char>
+ unspecified-type2 quoted(const Char* string, Char escape='\\', Char delim='\"');
+
+ // manipulator for non-const std::basic_string&
+
+ template <class Char, class Traits, class Alloc>
+ unspecified-type3 quoted(std::basic_string<Char, Traits, Alloc>& string, Char escape='\\', Char delim='\"');
+ }
+}
+unspecified_type1, unspecified_type2,
+and unspecified_type3 are implementation supplied
+types with implementation supplied operator<<:
++template <class Char, class Traits> + std::basic_ostream<Char, Traits>& + operator<<(std::basic_ostream<Char, Traits>& os, const+unspecified_typeN& proxy);Effects: Inserts characters into
+os:+
+- +
delim.- Each character in
+string. If the character to be output is + equal toescapeordelim, as determined by+ operator==, first outputescape.- +
delim.Remarks:
+string,escape, anddelim+have the type and value of the corresponding arguments of the call to the+quotedfunction that constructedproxy.Returns:
+os.
unspecified_type3 is an implementation supplied
+type with an implementation supplied operator>>:
++template <class Char, class Traits> + std::basic_istream<Char, Traits>& + operator>>(std::basic_istream<Char, Traits>& is, const+unspecified_type3& proxy);Effects: Extracts characters from
+os:+
+- If the first character extracted is equal to delim, as determined by +
+operator==, then:+
+- Turn off the
+skipwsflag.- +
string.clear()- Until an unescaped
+delimcharacter is reached, extract + characters fromosand append them tostring, + except that if anescapeis reached, ignore it and append the + next character tostring.- Discard the final
+delimcharacter.- Restore the
+skipwsflag to its original value.- Otherwise,
+os >> string.Remarks:
+string,escape, anddelim+have the type and value of the corresponding arguments of the call to the+quotedfunction that constructedproxy.Returns:
+is.
The quoted() stream manipulator emerged from discussions on the
+Boost developers mailing list. Participants included Beman Dawes, Rob Stewart,
+Alexander Lamaison, Eric Niebler, Vicente Botet, Andrey Semashev, Phil Richards,
+and Rob Murray. Eric Niebler's suggestions provided the basis for the name and
+form of the templates.
© Copyright Beman Dawes, 2002, 2006, 2007, 2009, 2010
+Distributed under the Boost Software License, Version 1.0. See +www.boost.org/LICENSE_1_0.txt
+Revised +18 June 2010
+ + + \ No newline at end of file diff --git a/include/boost/io/quoted_manip.hpp b/include/boost/io/quoted_manip.hpp index 325f14b..48253d3 100644 --- a/include/boost/io/quoted_manip.hpp +++ b/include/boost/io/quoted_manip.hpp @@ -1,12 +1,16 @@ +// boost/io/quoted_manip.hpp ---------------------------------------------------------// + // Copyright Beman Dawes 2010 // Distributed under the Boost Software License, Version 1.0. // See http://www.boost.org/LICENSE_1_0.txt +// Library home page http://www.boost.org/libs/io + //--------------------------------------------------------------------------------------// -#ifndef BOOST_QUOTE_MANIP -#define BOOST_QUOTE_MANIP +#ifndef BOOST_IO_QUOTED_MANIP +#define BOOST_IO_QUOTED_MANIP #include