diff --git a/include/crucible/spanner.h b/include/crucible/spanner.h
deleted file mode 100644
index 8679f95..0000000
--- a/include/crucible/spanner.h
+++ /dev/null
@@ -1,167 +0,0 @@
-#ifndef CRUCIBLE_SPANNER_H
-#define CRUCIBLE_SPANNER_H
-
-#include "crucible/error.h"
-
-#include <memory>
-
-namespace crucible {
-
-	using namespace std;
-
-	// C++20 is already using the name "span" for something similar.
-	template <class T, class Head = T*, class Iter = Head>
-	class Spanner {
-	public:
-		using iterator = Iter;
-		using head_pointer = Head;
-		using value_type = T;
-
-		template <class Container>
-		Spanner(Container& container);
-
-		Spanner(head_pointer begin, iterator end);
-		Spanner(size_t size, head_pointer begin);
-		Spanner() = default;
-		Spanner &operator=(const Spanner &that) = default;
-		iterator begin() const;
-		iterator end() const;
-		value_type *data() const;
-		value_type &at(size_t n) const;
-		size_t size() const;
-		bool empty() const;
-		void clear();
-		value_type &operator[](size_t n) const;
-		iterator erase(iterator first, iterator last);
-		iterator erase(iterator first);
-	private:
-		head_pointer	m_begin;
-		size_t		m_size;
-	};
-
-	template <class Container, class Head = typename Container::value_type *, class Iter = Head>
-	Spanner<typename Container::value_type, Head, Iter> make_spanner(Container &container)
-	{
-		return Spanner<typename Container::value_type, Head, Iter>(container);
-	}
-
-	// This template is an attempt to turn a shared_ptr to a container
-	// into a range view that can be cheaply passed around.
-	// It probably doesn't quite work in the general case.
-	template <class Container, class Head = shared_ptr<typename Container::value_type>, class Iter = typename Container::value_type *>
-	Spanner<typename Container::value_type, Head, Iter> make_spanner(shared_ptr<Container> &cont_ptr)
-	{
-		shared_ptr<typename Container::value_type> head(cont_ptr, cont_ptr->data());
-		size_t const size = cont_ptr->size();
-		return Spanner<typename Container::value_type, Head, Iter>(size, head);
-	}
-
-	template <class T, class Head, class Iter>
-	template <class Container>
-	Spanner<T, Head, Iter>::Spanner(Container &container) :
-		m_begin(container.data()),
-		m_size(container.size())
-	{
-	}
-
-	template <class T, class Head, class Iter>
-	Spanner<T, Head, Iter>::Spanner(head_pointer begin, iterator end) :
-		m_begin(begin),
-		m_size(end - begin)
-	{
-	}
-
-	template <class T, class Head, class Iter>
-	Spanner<T, Head, Iter>::Spanner(size_t size, head_pointer begin) :
-		m_begin(begin),
-		m_size(size)
-	{
-	}
-
-	template <class T, class Head, class Iter>
-	typename Spanner<T, Head, Iter>::iterator
-	Spanner<T, Head, Iter>::erase(iterator first, iterator last)
-	{
-		auto end = m_begin + m_size;
-		if (first == m_begin) {
-			THROW_CHECK0(invalid_argument, last <= end);
-			m_begin = last;
-			return last;
-		}
-		if (last == end) {
-			THROW_CHECK0(invalid_argument, m_begin <= first);
-			m_size = first - m_begin;
-			return first;
-		}
-		THROW_ERROR(invalid_argument, "first != begin() and last != end()");
-	}
-
-	template <class T, class Head, class Iter>
-	typename Spanner<T, Head, Iter>::iterator
-	Spanner<T, Head, Iter>::erase(iterator first)
-	{
-		return erase(first, first + 1);
-	}
-
-	template <class T, class Head, class Iter>
-	typename Spanner<T, Head, Iter>::value_type &
-	Spanner<T, Head, Iter>::operator[](size_t n) const
-	{
-		return at(n);
-	}
-
-	template <class T, class Head, class Iter>
-	void
-	Spanner<T, Head, Iter>::clear()
-	{
-		m_begin = head_pointer();
-		m_size = 0;
-	}
-
-	template <class T, class Head, class Iter>
-	bool
-	Spanner<T, Head, Iter>::empty() const
-	{
-		return m_size == 0;
-	}
-
-	template <class T, class Head, class Iter>
-	size_t
-	Spanner<T, Head, Iter>::size() const
-	{
-		return m_size;
-	}
-
-	template <class T, class Head, class Iter>
-	typename Spanner<T, Head, Iter>::value_type *
-	Spanner<T, Head, Iter>::data() const
-	{
-		return &(*m_begin);
-	}
-
-	template <class T, class Head, class Iter>
-	typename Spanner<T, Head, Iter>::iterator
-	Spanner<T, Head, Iter>::begin() const
-	{
-		return data();
-	}
-
-	template <class T, class Head, class Iter>
-	typename Spanner<T, Head, Iter>::iterator
-	Spanner<T, Head, Iter>::end() const
-	{
-		return data() + m_size;
-	}
-
-	template <class T, class Head, class Iter>
-	typename Spanner<T, Head, Iter>::value_type &
-	Spanner<T, Head, Iter>::at(size_t n) const
-	{
-		THROW_CHECK2(out_of_range, n, size(), n < size());
-		return *(data() + n);
-	}
-
-}
-
-
-#endif // CRUCIBLE_SPANNER_H