Conditional expression

select()

conditional selection with mask
template<class T, class A>
inline batch<T, A> xsimd::select(batch_bool<T, A> const &cond, batch<T, A> const &true_br, batch<T, A> const &false_br) noexcept

Ternary operator for batches: selects values from the batches true_br or false_br depending on the boolean values in the constant batch cond.

Equivalent to 

for(std::size_t i = 0; i < N; ++i)
    res[i] = cond[i] ? true_br[i] : false_br[i];

Parameters:

  • cond – batch condition.

  • true_br – batch values for truthy condition.

  • false_br – batch value for falsy condition.

Returns:

the result of the selection.

template<class T, class A, bool... Values>
inline batch<T, A> xsimd::select(batch_bool_constant<batch<T, A>, Values...> const &cond, batch<T, A> const &true_br, batch<T, A> const &false_br) noexcept

Ternary operator for batches: selects values from the batches true_br or false_br depending on the boolean values in the constant batch cond.

Equivalent to 

for(std::size_t i = 0; i < N; ++i)
    res[i] = cond[i] ? true_br[i] : false_br[i];

Parameters:

  • cond – constant batch condition.

  • true_br – batch values for truthy condition.

  • false_br – batch value for falsy condition.

Returns:

the result of the selection.

In the specific case when one needs to conditionnaly increment or decrement a batch based on a mask, incr_if() and decr_if() provide specialized version.