CompileTimeDerivativesMaterialInternal::details Namespace Reference

Functions
template<std::size_t first, std::size_t second, std::size_t... tail>
constexpr bool	is_sorted ()
	Check if the given index sequence is sorted ()internal function)
template<std::size_t N>
constexpr std::size_t	factorial ()
	Compile time evaluation of the factorial of N.
template<std::size_t N, std::size_t M>
constexpr std::size_t	num_derivatives ()
	Number of distinct order N derivatives of a function with M variables.
template<std::size_t... first, std::size_t... second>
constexpr auto	merge (std::index_sequence< first... >, std::index_sequence< second... >)
	Merge two index sequences into one.
template<std::size_t Nmax, std::size_t first, std::size_t... tail>
constexpr auto	increment (std::index_sequence< first, tail... >)
	Increment the first number in an index sequence, but roll over into the next number if it reaches Nmax.
template<std::size_t M, std::size_t... N>
constexpr std::size_t	total_derivatives (std::index_sequence< N... >)
	Compute the total number of distinct derivatives for all orders N.
template<std::size_t... Ns>
constexpr auto	zeroes (std::index_sequence< Ns... >)
	Take an index sequence and return an index sequence of the same length with all entries replaced by zeroes.

Function Documentation

factorial()

template<std::size_t N>

constexpr std::size_t CompileTimeDerivativesMaterialInternal::details::factorial ( )

constexpr

Compile time evaluation of the factorial of N.

Definition at line 42 of file CompileTimeDerivativesMaterialInternal.h.

{
  if constexpr (N == 0)
    return 1;
  else if constexpr (N == 1)
    return 1;
  else
    return N * factorial<N - 1>();
}

Referenced by factorial(), and num_derivatives().

increment()

template<std::size_t Nmax, std::size_t first, std::size_t... tail>

constexpr auto CompileTimeDerivativesMaterialInternal::details::increment ( std::index_sequence< first, tail... >  )

constexpr

Increment the first number in an index sequence, but roll over into the next number if it reaches Nmax.

This basically increments a base-Nmax number with its digits in reverse!

Definition at line 78 of file CompileTimeDerivativesMaterialInternal.h.

{
  if constexpr (first + 1 == Nmax)
  {
    if constexpr (sizeof...(tail) == 0)
      return std::index_sequence<>{};
    else
      return merge(std::index_sequence<0>{}, increment<Nmax>(std::index_sequence<tail...>{}));
  }
  else
    return std::index_sequence<first + 1, tail...>{};
}

is_sorted()

template<std::size_t first, std::size_t second, std::size_t... tail>

constexpr bool CompileTimeDerivativesMaterialInternal::details::is_sorted ( )

constexpr

Check if the given index sequence is sorted ()internal function)

Definition at line 24 of file CompileTimeDerivativesMaterialInternal.h.

{
  if constexpr (first <= second)
  {
    if constexpr (sizeof...(tail) == 0)
      return true;
    else
      return is_sorted<second, tail...>();
  }
  else
    return false;
}

Referenced by is_sorted(), and CompileTimeDerivativesMaterialInternal::is_sorted().

merge()

template<std::size_t... first, std::size_t... second>

constexpr auto CompileTimeDerivativesMaterialInternal::details::merge ( std::index_sequence< first... >  , std::index_sequence< second... >    )

constexpr

Merge two index sequences into one.

Definition at line 67 of file CompileTimeDerivativesMaterialInternal.h.

{
  return std::index_sequence<first..., second...>{};
}

Referenced by increment().

num_derivatives()

template<std::size_t N, std::size_t M>

constexpr std::size_t CompileTimeDerivativesMaterialInternal::details::num_derivatives ( )

constexpr

Number of distinct order N derivatives of a function with M variables.

Definition at line 57 of file CompileTimeDerivativesMaterialInternal.h.

{
  return factorial<N + M - 1>() / (factorial<N>() * factorial<M - 1>());
}

total_derivatives()

template<std::size_t M, std::size_t... N>

constexpr std::size_t CompileTimeDerivativesMaterialInternal::details::total_derivatives ( std::index_sequence< N... >  )

constexpr

Compute the total number of distinct derivatives for all orders N.

Definition at line 96 of file CompileTimeDerivativesMaterialInternal.h.

{
  return (num_derivatives<N, M>() + ...);
}

zeroes()

template<std::size_t... Ns>

constexpr auto CompileTimeDerivativesMaterialInternal::details::zeroes ( std::index_sequence< Ns... >  )

constexpr

Take an index sequence and return an index sequence of the same length with all entries replaced by zeroes.

Definition at line 107 of file CompileTimeDerivativesMaterialInternal.h.

{
  return std::index_sequence<(void(Ns), 0)...>{};
}

Referenced by CompileTimeDerivativesMaterialInternal::zeroes().