Some cleanup in alspan.h

1 files changed, 31 insertions, 21 deletions

diff --git a/common/alspan.h b/common/alspan.h
index 7be07354..c1ad6f9e 100644
--- a/common/alspan.h
+++ b/common/alspan.h
@@ -10,11 +10,11 @@
 namespace al {
 
 template<typename T>
-constexpr auto size(T &cont) -> decltype(cont.size())
+constexpr auto size(T &cont) noexcept(noexcept(cont.size())) -> decltype(cont.size())
 { return cont.size(); }
 
 template<typename T>
-constexpr auto size(const T &cont) -> decltype(cont.size())
+constexpr auto size(const T &cont) noexcept(noexcept(cont.size())) -> decltype(cont.size())
 { return cont.size(); }
 
 template<typename T, size_t N>
@@ -27,11 +27,11 @@ constexpr size_t size(std::initializer_list<T> list) noexcept
 
 
 template<typename T>
-constexpr auto data(T &cont) -> decltype(cont.data())
+constexpr auto data(T &cont) noexcept(noexcept(cont.data())) -> decltype(cont.data())
 { return cont.data(); }
 
 template<typename T>
-constexpr auto data(const T &cont) -> decltype(cont.data())
+constexpr auto data(const T &cont) noexcept(noexcept(cont.data())) -> decltype(cont.data())
 { return cont.data(); }
 
 template<typename T, size_t N>
@@ -43,7 +43,9 @@ constexpr const T* data(std::initializer_list<T> list) noexcept
 { return list.begin(); }
 
 
-template<typename T, size_t E=static_cast<size_t>(-1)>
+constexpr size_t dynamic_extent{static_cast<size_t>(-1)};
+
+template<typename T, size_t E=dynamic_extent>
 class span;
 
 namespace detail_ {
@@ -82,8 +84,6 @@ namespace detail_ {
 
 template<typename T, size_t E>
 class span {
-    static constexpr size_t dynamic_extent{static_cast<size_t>(-1)};
-
 public:
     using element_type = T;
     using value_type = std::remove_cv_t<T>;
@@ -109,12 +109,15 @@ public:
     constexpr span(element_type (&arr)[E]) noexcept : span{al::data(arr), al::size(arr)} { }
     constexpr span(std::array<value_type,E> &arr) noexcept : span{al::data(arr), al::size(arr)} { }
     template<REQUIRES(std::is_const<element_type>::value)>
-    constexpr span(const std::array<value_type,E> &arr) noexcept : span{al::data(arr), al::size(arr)} { }
+    constexpr span(const std::array<value_type,E> &arr) noexcept
+      : span{al::data(arr), al::size(arr)}
+    { }
     template<typename U, REQUIRES(IS_VALID_CONTAINER(U))>
     constexpr span(U &cont) : span{al::data(cont), al::size(cont)} { }
     template<typename U, REQUIRES(IS_VALID_CONTAINER(const U))>
     constexpr span(const U &cont) : span{al::data(cont), al::size(cont)} { }
-    template<typename U, REQUIRES(!std::is_same<element_type,U>::value && std::is_convertible<U(*)[],element_type(*)[]>::value)>
+    template<typename U, REQUIRES(!std::is_same<element_type,U>::value
+        && std::is_convertible<U(*)[],element_type(*)[]>::value)>
     constexpr span(const span<U,E> &span_) noexcept : span{al::data(span_), al::size(span_)} { }
     constexpr span(const span&) noexcept = default;
 
@@ -136,8 +139,10 @@ public:
 
     constexpr reverse_iterator rbegin() const noexcept { return reverse_iterator{end()}; }
     constexpr reverse_iterator rend() const noexcept { return reverse_iterator{begin()}; }
-    constexpr const_reverse_iterator crbegin() const noexcept { return const_reverse_iterator{cend()}; }
-    constexpr const_reverse_iterator crend() const noexcept { return const_reverse_iterator{cbegin()}; }
+    constexpr const_reverse_iterator crbegin() const noexcept
+    { return const_reverse_iterator{cend()}; }
+    constexpr const_reverse_iterator crend() const noexcept
+    { return const_reverse_iterator{cbegin()}; }
 
     template<size_t C>
     constexpr span<element_type,C> first() const
@@ -167,16 +172,15 @@ public:
      */
     constexpr span<element_type,dynamic_extent> first(size_t count) const;
     constexpr span<element_type,dynamic_extent> last(size_t count) const;
-    constexpr span<element_type,dynamic_extent> subspan(size_t offset, size_t count=dynamic_extent) const;
+    constexpr span<element_type,dynamic_extent> subspan(size_t offset,
+        size_t count=dynamic_extent) const;
 
 private:
     pointer mData{nullptr};
 };
 
 template<typename T>
-class span<T,static_cast<size_t>(-1)> {
-    static constexpr size_t dynamic_extent{static_cast<size_t>(-1)};
-
+class span<T,dynamic_extent> {
 public:
     using element_type = T;
     using value_type = std::remove_cv_t<T>;
@@ -193,7 +197,7 @@ public:
     using reverse_iterator = std::reverse_iterator<iterator>;
     using const_reverse_iterator = std::reverse_iterator<const_iterator>;
 
-    static constexpr size_t extent{static_cast<size_t>(-1)};
+    static constexpr size_t extent{dynamic_extent};
 
     constexpr span() noexcept = default;
     constexpr span(pointer ptr, index_type count) : mData{ptr}, mDataEnd{ptr+count} { }
@@ -203,12 +207,15 @@ public:
     template<size_t N>
     constexpr span(std::array<value_type,N> &arr) noexcept : span{al::data(arr), al::size(arr)} { }
     template<size_t N, REQUIRES(std::is_const<element_type>::value)>
-    constexpr span(const std::array<value_type,N> &arr) noexcept : span{al::data(arr), al::size(arr)} { }
+    constexpr span(const std::array<value_type,N> &arr) noexcept
+      : span{al::data(arr), al::size(arr)}
+    { }
     template<typename U, REQUIRES(IS_VALID_CONTAINER(U))>
     constexpr span(U &cont) : span{al::data(cont), al::size(cont)} { }
     template<typename U, REQUIRES(IS_VALID_CONTAINER(const U))>
     constexpr span(const U &cont) : span{al::data(cont), al::size(cont)} { }
-    template<typename U, size_t N, REQUIRES((!std::is_same<element_type,U>::value || extent != N) && std::is_convertible<U(*)[],element_type(*)[]>::value)>
+    template<typename U, size_t N, REQUIRES((!std::is_same<element_type,U>::value || extent != N)
+        && std::is_convertible<U(*)[],element_type(*)[]>::value)>
     constexpr span(const span<U,N> &span_) noexcept : span{al::data(span_), al::size(span_)} { }
     constexpr span(const span&) noexcept = default;
 
@@ -231,8 +238,10 @@ public:
 
     constexpr reverse_iterator rbegin() const noexcept { return reverse_iterator{end()}; }
     constexpr reverse_iterator rend() const noexcept { return reverse_iterator{begin()}; }
-    constexpr const_reverse_iterator crbegin() const noexcept { return const_reverse_iterator{cend()}; }
-    constexpr const_reverse_iterator crend() const noexcept { return const_reverse_iterator{cbegin()}; }
+    constexpr const_reverse_iterator crbegin() const noexcept
+    { return const_reverse_iterator{cend()}; }
+    constexpr const_reverse_iterator crend() const noexcept
+    { return const_reverse_iterator{cbegin()}; }
 
     template<size_t C>
     constexpr span<element_type,C> first() const
@@ -279,7 +288,8 @@ constexpr inline auto span<T,E>::last(size_t count) const -> span<element_type,d
 }
 
 template<typename T, size_t E>
-constexpr inline auto span<T,E>::subspan(size_t offset, size_t count) const -> span<element_type,dynamic_extent>
+constexpr inline auto span<T,E>::subspan(size_t offset, size_t count) const
+    -> span<element_type,dynamic_extent>
 {
     return (offset > size()) ? span<element_type>{} :
         (count >= size()-offset) ? span<element_type>{mData+offset, mData+extent} :