Florent Rougon
bd3c351f1f
This function template is useful to get the value of a member of a scoped enumeration, without having to hardcode its type while casting it.
141 lines
3.8 KiB
C++
141 lines
3.8 KiB
C++
/**
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* \file sg_inlines.h
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* Various inline template definitions.
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*/
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// Written by Norman Vine, started June 2000.
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//
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// Copyright (C) 2000 Norman Vine - nhv@cape.com
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//
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// This library is free software; you can redistribute it and/or
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// modify it under the terms of the GNU Library General Public
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// License as published by the Free Software Foundation; either
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// version 2 of the License, or (at your option) any later version.
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//
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// This library is distributed in the hope that it will be useful,
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// but WITHOUT ANY WARRANTY; without even the implied warranty of
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// MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU
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// Library General Public License for more details.
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//
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// You should have received a copy of the GNU General Public License
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// along with this program; if not, write to the Free Software
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// Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301, USA.
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//
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// $Id$
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#include <type_traits>
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#include <utility>
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#ifndef _SG_INLINES_H
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#define _SG_INLINES_H
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// return the sign of a value
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template <class T>
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inline int SG_SIGN(const T x) {
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return x < T(0) ? -1 : 1;
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}
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// return the minimum of two values
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template <class T>
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inline T SG_MIN2(const T a, const T b) {
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return a < b ? a : b;
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}
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// return the minimum of three values
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template <class T>
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inline T SG_MIN3( const T a, const T b, const T c) {
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return (a < b ? SG_MIN2 (a, c) : SG_MIN2 (b, c));
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}
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// return the maximum of two values
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template <class T>
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inline T SG_MAX2(const T a, const T b) {
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return a > b ? a : b;
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}
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// return the maximum of three values
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template <class T>
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inline T SG_MAX3 (const T a, const T b, const T c) {
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return (a > b ? SG_MAX2 (a, c) : SG_MAX2 (b, c));
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}
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// return the minimum and maximum of three values
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template <class T>
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inline void SG_MIN_MAX3 ( T &min, T &max, const T a, const T b, const T c) {
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if( a > b ) {
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if( a > c ) {
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max = a;
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min = SG_MIN2 (b, c);
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} else {
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max = c;
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min = SG_MIN2 (a, b);
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}
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} else {
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if( b > c ) {
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max = b;
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min = SG_MIN2 (a, c);
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} else {
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max = c;
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min = SG_MIN2 (a, b);
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}
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}
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}
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// swap two values
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template <class T>
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inline void SG_SWAP( T &a, T &b) {
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T c = a; a = b; b = c;
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}
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// clamp a value to lie between min and max
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template <class T>
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inline void SG_CLAMP_RANGE(T &x, const T min, const T max ) {
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if ( x < min ) { x = min; }
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if ( x > max ) { x = max; }
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}
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// normalize a value to lie between min and max
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template <class T>
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inline void SG_NORMALIZE_RANGE( T &val, const T min, const T max ) {
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T step = max - min;
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while( val >= max ) val -= step;
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while( val < min ) val += step;
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}
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// avoid an 'unused parameter' compiler warning.
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#define SG_UNUSED(x) (void)x
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// easy way to disable the copy constructor and assignment operator
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// on an object
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#define SG_DISABLE_COPY(Class) \
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Class(const Class &); \
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Class &operator=(const Class &);
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namespace simgear {
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// A swap() that is guaranteed to be 'noexcept' as long as compilation
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// succeeds. Idea and implementation from
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// <https://akrzemi1.wordpress.com/2011/06/10/using-noexcept/>.
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template<typename T>
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void noexceptSwap(T& a, T& b) noexcept
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{
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using std::swap;
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static_assert(noexcept(swap(a, b)), "this swap() is not 'noexcept'" );
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swap(a, b);
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}
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// Cast an enum value to its underlying type (useful with scoped enumerations).
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//
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// Example: enum class MyEnum { first = 1, second };
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// auto e = MyEnum::second;
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// std::string msg = "MyEnum::second is " +
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// std::to_string(simgear::enumValue(e));
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template <typename T>
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constexpr typename std::underlying_type<T>::type enumValue(T e) {
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return static_cast<typename std::underlying_type<T>::type>(e);
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}
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} // of namespace simgear
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#endif // _SG_INLINES_H
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