ImageLeftAction

template<typename TElementType, typename TPointType, typename = void>
struct ImageLeftAction

Adapter for the value of a left action.

Defined in adapters.hpp.

Specialisations of this struct should be stateless trivially default constructible with a call operator of signature void operator()(TPointType& res, TElementType const& x, TPointType const& pt) const (possibly noexcept, inline and/or constexpr also).

The call operator should change res in-place to contain the image of the point pt under the left action of the element x. The purpose of the 1st parameter is to avoid repeated allocations of memory to hold temporary points that are discarded soon after they are created.

The third template parameter exists for SFINAE.

Example

template <>
struct ImageLeftAction<BMat8, BMat8> {
  void operator()(BMat8& res, BMat8 pt, BMat8 x) const noexcept {
    res = (x * pt).col_space_basis();
  }
};

Template Parameters:

• TElementType – the type of the elements of a semigroup.

• TPointType – the type of the points acted on.