Add copy assignment operator to `strided_bounds`
`strided_bounds` defines copy constructor, but lacks copy assignment
operator
diff --git a/include/span.h b/include/span.h
index 74da1aa..cb045cb 100644
--- a/include/span.h
+++ b/include/span.h
@@ -685,6 +685,8 @@
constexpr strided_bounds(const strided_bounds &) noexcept = default;
+ constexpr strided_bounds & operator=(const strided_bounds &) noexcept = default;
+
constexpr strided_bounds(const value_type(&values)[rank], index_type strides)
: m_extents(values), m_strides(std::move(strides))
{}