• Read the characters of the next line from strm into the string str.
• All characters, including leading whitespaces, are extracted until any of the following happens:
– strm.good() is false (which might cause an appropriate exception)
– delim or strm.widen(’
’) is extracted
– str.max_size() characters are stored
• The line delimiter is extracted but not appended.
• The internal memory is reallocated accordingly.
• istream is the istream type basic_istream according to the character type (see Sec-
tion 15.2.1, page 748).
• The overloads for rvalue references are available since C++11.