C++ Library containing a lot of needful things: Stack Trace, Command Line Parser, Resource Handling, Configuration Files, Unix Command Execution, Directories, Regular Expressions, Tokenizer, Function Trace, Standard Extensions.
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/** @file
$Id$
$Date$
$Author$
@copy © Marc Wäckerlin
@license LGPL, see file <a href="license.html">COPYING</a>
*/
#ifndef __MRW__STDEXT_HPP__
#define __MRW__STDEXT_HPP__
#include <string>
#include <iostream>
#include <algorithm>
namespace mrw {
/** @addtogroup StdExt
*/
//@{
/** @defgroup stdextFunction Useful Global Functions
- @ref getline read exactly one line from a stream
- @ref ifelse implements a dual <code>?:</code> operator, like:
<code>a&nbsp;?&nbsp;a&nbsp;:&nbsp;b</code>
@section stdextGetline Read Line
The global functions mrw::getline read exactly one line from a
stream, without the need of a buffer. It is therefore guaranteed
that a whole line is read, regardless of the length of the
line. The result is returned as std::string.
@code
// first syntax returns a string:
std::string line(mrw::getline(std::cin));
// second syntax returns the stream:
while (mrw::getline(std::cin, line))
std::cout<<"Read: "<<line<<std::endl;
@endcode
*/
//@{
/** @brief Dual <code>?:</code> operation:
<code>a&nbsp;?&nbsp;a&nbsp;:&nbsp;b</code>
If the first parameter is not @c 0, then it is returned,
otherwise the second parameter is returned. It is equivalent to
the construct: <code>a&nbsp;?&nbsp;a&nbsp;:&nbsp;b</code>, but without
the side effect of duplicated evaluation of parameter
<code>a</code>.
Older gcc compiler implemented the non standard extension of
<code>a?:b</code>, which was exactly the same.
@param a criteria that is checked and returned if not @c 0
@param b alternative value to be returned if @c a is @c 0
@return <code>a&nbsp;?&nbsp;a&nbsp;:&nbsp;b</code>
@pre \#include <mrw/stdext.hpp>
@pre @c T must be convertible to @c bool
*/
template<typename T> const T& ifelse(const T& a, const T& b) {
return a?a:b;
}
/** @brief Dual <code>?:</code> operation:
<code>a&nbsp;?&nbsp;a&nbsp;:&nbsp;b</code>
@copydoc ifelse(const T& a, const T& b) */
template<typename T> const T* ifelse(const T* a, const T* b) {
return a?a:b;
}
/** @brief read one line from a stream
Reads one line from a stream, up to delimiter @c d.
The delimiter is not appended to the string.
@param is the stream to read from
@param d the end of line delimiter
@return the line read from the stream
@pre \#include <mrw/stdext.hpp>
*/
std::string getline(std::istream& is, char d = '\n');
/** @brief read one line from a stream
Reads one line from a stream, up to delimiter @c d.
The delimiter is not appended to the string.
@param is the stream to read from
@param s the string to place the line in
@param d the end of line delimiter
@return @c s: the line read from the stream
@return the stream after extraction of line
@pre \#include <mrw/stdext.hpp>
*/
std::istream& getline(std::istream& is, std::string& s, char d = '\n');
//@}
//@}
}
#endif