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- [/ QuickBook Document version 1.5 ]
- [section:clamp clamp]
- [/license
- Copyright (c) 2010-2012 Marshall Clow
- Distributed under the Boost Software License, Version 1.0.
- (See accompanying file LICENSE_1_0.txt or copy at
- http://www.boost.org/LICENSE_1_0.txt)
- ]
- The header file clamp.hpp contains two functions for "clamping" a value between a pair of boundary values.
- [heading clamp]
- The function `clamp (v, lo, hi)` returns:
- * lo if v < lo
- * hi if hi < v
- * otherwise, v
- Note: using `clamp` with floating point numbers may give unexpected results if one of the values is `NaN`.
- There is also a version that allows the caller to specify a comparison predicate to use instead of `operator <`.
- ``
- template<typename T>
- const T& clamp ( const T& val, const T& lo, const T& hi );
- template<typename T, typename Pred>
- const T& clamp ( const T& val, const T& lo, const T& hi, Pred p );
- ``
- The following code: ``
- int foo = 23;
- foo = clamp ( foo, 1, 10 );
- ``
- will leave `foo` with a value of 10
- Complexity:
- `clamp` will make either one or two calls to the comparison predicate before returning one of the three parameters.
- [heading clamp_range]
- There are also four range-based versions of clamp, that apply clamping to a series of values. You could write them yourself with std::transform and bind, like this: `std::transform ( first, last, out, bind ( clamp ( _1, lo, hi )))`, but they are provided here for your convenience.
- ``
- template<typename InputIterator, typename OutputIterator>
- OutputIterator clamp_range ( InputIterator first, InputIterator last, OutputIterator out,
- typename std::iterator_traits<InputIterator>::value_type lo,
- typename std::iterator_traits<InputIterator>::value_type hi );
- template<typename Range, typename OutputIterator>
- OutputIterator clamp_range ( const Range &r, OutputIterator out,
- typename std::iterator_traits<typename boost::range_iterator<const Range>::type>::value_type lo,
- typename std::iterator_traits<typename boost::range_iterator<const Range>::type>::value_type hi );
- template<typename InputIterator, typename OutputIterator, typename Pred>
- OutputIterator clamp_range ( InputIterator first, InputIterator last, OutputIterator out,
- typename std::iterator_traits<InputIterator>::value_type lo,
- typename std::iterator_traits<InputIterator>::value_type hi, Pred p );
- template<typename Range, typename OutputIterator, typename Pred>
- OutputIterator clamp_range ( const Range &r, OutputIterator out,
- typename std::iterator_traits<typename boost::range_iterator<const Range>::type>::value_type lo,
- typename std::iterator_traits<typename boost::range_iterator<const Range>::type>::value_type hi,
- Pred p );
- ``
- [endsect]
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