Make iterator access functions on span constexpr (#612)
As per feedback on span received during the C++ standardization discussions.
diff --git a/include/gsl/span b/include/gsl/span
index fa76ed5..1c8b2e5 100644
--- a/include/gsl/span
+++ b/include/gsl/span
@@ -482,17 +482,17 @@
constexpr pointer data() const GSL_NOEXCEPT { return storage_.data(); }
// [span.iter], span iterator support
- iterator begin() const GSL_NOEXCEPT { return {this, 0}; }
- iterator end() const GSL_NOEXCEPT { return {this, length()}; }
+ constexpr iterator begin() const GSL_NOEXCEPT { return {this, 0}; }
+ constexpr iterator end() const GSL_NOEXCEPT { return {this, length()}; }
- const_iterator cbegin() const GSL_NOEXCEPT { return {this, 0}; }
- const_iterator cend() const GSL_NOEXCEPT { return {this, length()}; }
+ constexpr const_iterator cbegin() const GSL_NOEXCEPT { return {this, 0}; }
+ constexpr const_iterator cend() const GSL_NOEXCEPT { return {this, length()}; }
- reverse_iterator rbegin() const GSL_NOEXCEPT { return reverse_iterator{end()}; }
- reverse_iterator rend() const GSL_NOEXCEPT { return reverse_iterator{begin()}; }
+ constexpr reverse_iterator rbegin() const GSL_NOEXCEPT { return reverse_iterator{end()}; }
+ constexpr reverse_iterator rend() const GSL_NOEXCEPT { return reverse_iterator{begin()}; }
- const_reverse_iterator crbegin() const GSL_NOEXCEPT { return const_reverse_iterator{cend()}; }
- const_reverse_iterator crend() const GSL_NOEXCEPT { return const_reverse_iterator{cbegin()}; }
+ constexpr const_reverse_iterator crbegin() const GSL_NOEXCEPT { return const_reverse_iterator{cend()}; }
+ constexpr const_reverse_iterator crend() const GSL_NOEXCEPT { return const_reverse_iterator{cbegin()}; }
private:
// this implementation detail class lets us take advantage of the