One< Element, typename >

template<typename Element, typename = void>
struct libsemigroups::One< Element, typename >

Specialisations of this struct should be stateless trivially default constructible with two call operator of signatures:

1. Element operator()(size_t n) const (possibly noexcept, inline and/or constexpr also) returning a multiplicative identity element for the category Element and with Degree<Element>()(x) equal to the parameter n. For example, if Element is a type of n x n matrices, then this should return the n x n identity matrix.
2. Element operator()(T const&) const (possibly noexcept, inline and/or constexpr also). This could be implemented as:

   Element operator()(Element const& x) const noexcept {
     return this->operator()(Degree<Element>()(x));
   }

Template Parameters

Element

the type of the elements of a semigroup.

The second template parameter exists for SFINAE.

Used by:

• ActionTraits
• FroidurePinTraits
• SchreierSimsTraits

Example

template <typename T>
struct One<
    T,
    typename std::enable_if<std::is_base_of<PTransf16, T>::value>::type> {
  T operator()(size_t = 0) const noexcept {
    return T::one();
  }
 
  T operator()(T const&) const noexcept {
    return T::one();
  }
};

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The documentation for this struct was generated from the following file:

• /Users/jdm/libsemigroups/include/libsemigroups/adapters.hpp