2131. Member function getline taking a string as parameter

Section: 31.7.5.4 [istream.unformatted] Status: NAD Submitter: Loïc Joly Opened: 2012-03-05 Last modified: 2016-01-28

Priority: Not Prioritized

View all other issues in [istream.unformatted].

View all issues with NAD status.

Discussion:

I think the following code should be legal:

void f(std::istream& is)
{
  std::string s;
  is.getline(s); // Would be equivalent to std::getline(is, s)
}

[2013-04-20, Bristol]

Unanimous that this is a new feature request and not a issue.

Resolution: Tentatively NAD

Proposed resolution:

This wording is relative to N3376.

1. Change the class template basic_istream synopsis, 31.7.5.2 [istream], as indicated

   namespace std {
     template <class charT, class traits = char_traits<charT> >
     class basic_istream : virtual public basic_ios<charT,traits> {
     public:
       […]
       // 27.7.2.3 Unformatted input:
       […]
       basic_istream<charT,traits>& getline(char_type* s, streamsize n);
       basic_istream<charT,traits>& getline(char_type* s, streamsize n,
         char_type delim);
       template<class Allocator>
       basic_istream<charT,traits>& getline(basic_string<charT,traits,Allocator>& str);
       template<class Allocator>
       basic_istream<charT,traits>& getline(basic_string<charT,traits,Allocator>& str,
         char_type delim);
       […]
     };
   }
   

2. Insert the following two new prototype descriptions after 31.7.5.4 [istream.unformatted] paragraph 24:

   basic_istream<charT,traits>& getline(char_type* s, streamsize n);
   

   -24- Returns: getline(s,n,widen('\n'))

   template<class Allocator>
   basic_istream<charT,traits>& getline(basic_string<charT,traits,Allocator>& str);
   

   -??- Returns: std::getline(*this, str)

   template<class Allocator>
   basic_istream<charT,traits>& getline(basic_string<charT,traits,Allocator>& str, char_type delim);
   

   -??- Returns: std::getline(*this, str, delim)