fish-shell/muparser-2.2.5/include/muParserTemplateMagic.h

#ifndef MU_PARSER_TEMPLATE_MAGIC_H
#define MU_PARSER_TEMPLATE_MAGIC_H

#include <cmath>

namespace mu {
//-----------------------------------------------------------------------------------------------
//
// Compile time type detection
//
//-----------------------------------------------------------------------------------------------

/** \brief A class singling out integer types at compile time using
           template meta programming.
*/
template <typename T>
struct TypeInfo {
    static bool IsInteger() { return false; }
};

template <>
struct TypeInfo<char> {
    static bool IsInteger() { return true; }
};

template <>
struct TypeInfo<short> {
    static bool IsInteger() { return true; }
};

template <>
struct TypeInfo<int> {
    static bool IsInteger() { return true; }
};

template <>
struct TypeInfo<long> {
    static bool IsInteger() { return true; }
};

template <>
struct TypeInfo<unsigned char> {
    static bool IsInteger() { return true; }
};

template <>
struct TypeInfo<unsigned short> {
    static bool IsInteger() { return true; }
};

template <>
struct TypeInfo<unsigned int> {
    static bool IsInteger() { return true; }
};

template <>
struct TypeInfo<unsigned long> {
    static bool IsInteger() { return true; }
};

//-----------------------------------------------------------------------------------------------
//
// Standard math functions with dummy overload for integer types
//
//-----------------------------------------------------------------------------------------------

/** \brief A template class for providing wrappers for essential math functions.

  This template is spezialized for several types in order to provide a unified interface
  for parser internal math function calls regardless of the data type.
*/
template <typename T>
struct MathImpl {
    static T Sin(T v) { return sin(v); }
    static T Cos(T v) { return cos(v); }
    static T Tan(T v) { return tan(v); }
    static T ASin(T v) { return asin(v); }
    static T ACos(T v) { return acos(v); }
    static T ATan(T v) { return atan(v); }
    static T ATan2(T v1, T v2) { return atan2(v1, v2); }
    static T Sinh(T v) { return sinh(v); }
    static T Cosh(T v) { return cosh(v); }
    static T Tanh(T v) { return tanh(v); }
    static T ASinh(T v) { return log(v + sqrt(v * v + 1)); }
    static T ACosh(T v) { return log(v + sqrt(v * v - 1)); }
    static T ATanh(T v) { return ((T)0.5 * log((1 + v) / (1 - v))); }
    static T Log(T v) { return log(v); }
    static T Log2(T v) { return log(v) / log((T)2); }  // Logarithm base 2
    static T Log10(T v) { return log10(v); }           // Logarithm base 10
    static T Exp(T v) { return exp(v); }
    static T Abs(T v) { return (v >= 0) ? v : -v; }
    static T Sqrt(T v) { return sqrt(v); }
    static T Rint(T v) { return floor(v + (T)0.5); }
    static T Sign(T v) { return (T)((v < 0) ? -1 : (v > 0) ? 1 : 0); }
    static T Pow(T v1, T v2) { return std::pow(v1, v2); }
};
}

#endif