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       1              : #ifndef B8E086B0_F27F_43B8_9748_96B243918772
       2              : #define B8E086B0_F27F_43B8_9748_96B243918772
       3              : 
       4              : /// \file functions.h
       5              : /// \brief Mathematical functions for compile-time computations
       6              : ///
       7              : /// This file provides mathematical functions that can be evaluated at compile time.
       8              : /// The implementation uses modern C++17 constexpr functions for better readability
       9              : /// and maintainability compared to template metaprogramming approaches.
      10              : ///
      11              : /// \note All functions are constexpr and can be used in template parameters
      12              : ///       and other compile-time contexts.
      13              : 
      14              : #include "base/first_include.h" // IWYU pragma: keep
      15              : 
      16              : namespace tracking
      17              : {
      18              : namespace math
      19              : {
      20              : /// \brief Compile-time power function
      21              : ///
      22              : /// Computes x^N at compile time using a simple iterative approach.
      23              : /// This modern C++17 implementation replaces the previous template metaprogramming
      24              : /// approach, providing better readability and maintainability while maintaining
      25              : /// zero runtime overhead when used with compile-time constants.
      26              : ///
      27              : /// \tparam N The exponent (must be a compile-time constant, non-negative integer)
      28              : /// \tparam T The value type (must support multiplication)
      29              : /// \param x The base value
      30              : /// \return x raised to the power N
      31              : ///
      32              : /// \note This function is constexpr and can be used in template parameters
      33              : /// \note Negative exponents are not supported (would require floating-point division)
      34              : /// \note For runtime exponents, use std::pow from cmath
      35              : ///
      36              : /// Example usage:
      37              : /// \code{.cpp}
      38              : /// constexpr double result = tracking::math::pow<3>(2.0); // result = 8.0
      39              : /// constexpr int template_param = tracking::math::pow<4>(3); // can be used in templates
      40              : /// \endcode
      41              : template <int N, class T>
      42         1110 : constexpr T pow(T const x)
      43              : {
      44              :   if constexpr (N == 0)
      45              :   {
      46              :     return 1; // x^0 = 1 (mathematical convention)
      47              :   }
      48              :   else if constexpr (N == 1)
      49              :   {
      50              :     return x; // x^1 = x
      51              :   }
      52              :   else
      53              :   {
      54              :     // Iterative approach for N >= 2
      55         1110 :     T result = x;
      56         2204 :     for (int i = 1; i < N; ++i)
      57              :     {
      58         1158 :       result *= x;
      59              :     }
      60              :     return result;
      61              :   }
      62              : }
      63              : 
      64              : } // namespace math
      65              : } // namespace tracking
      66              : 
      67              : #endif // B8E086B0_F27F_43B8_9748_96B243918772