From ba48ef3949b242f473b0213fd8edf90774a4aa56 Mon Sep 17 00:00:00 2001
From: lumberyard-employee-dm
 <56135373+lumberyard-employee-dm@users.noreply.github.com>
Date: Wed, 16 Feb 2022 10:06:00 -0600
Subject: [PATCH] GCC Build fix. (#7659)

GCC doesn't accept accessing member variables inside the noexcept expression of a member function.

GCC also requires that template specializations for an inner template be outside of all classes.

Signed-off-by: lumberyard-employee-dm <56135373+lumberyard-employee-dm@users.noreply.github.com>
---
 .../AzCore/AzCore/std/ranges/ranges_adaptor.h | 12 ++--
 .../AzCore/AzCore/std/string/string_view.h    | 55 ++++++++++++-------
 2 files changed, 40 insertions(+), 27 deletions(-)

diff --git a/Code/Framework/AzCore/AzCore/std/ranges/ranges_adaptor.h b/Code/Framework/AzCore/AzCore/std/ranges/ranges_adaptor.h
index 6c814def5d..10e8998584 100644
--- a/Code/Framework/AzCore/AzCore/std/ranges/ranges_adaptor.h
+++ b/Code/Framework/AzCore/AzCore/std/ranges/ranges_adaptor.h
@@ -23,28 +23,28 @@ namespace AZStd::ranges::views::Internal
         {}
         template<class... Args>
         constexpr decltype(auto) operator()(Args&&... args) &
-            noexcept(noexcept(AZStd::invoke(m_outer, AZStd::invoke(m_inner, AZStd::forward<Args>(args)...))))
+            noexcept(noexcept(AZStd::invoke(declval<Outer>(), AZStd::invoke(declval<Inner>(), AZStd::forward<Args>(args)...))))
         {
             return AZStd::invoke(m_outer, AZStd::invoke(m_inner, AZStd::forward<Args>(args)...));
         }
         template<class... Args>
         constexpr decltype(auto) operator()(Args&&... args) const&
-            noexcept(noexcept(AZStd::invoke(m_outer, AZStd::invoke(m_inner, AZStd::forward<Args>(args)...))))
+            noexcept(noexcept(AZStd::invoke(declval<Outer>(), AZStd::invoke(declval<Inner>(), AZStd::forward<Args>(args)...))))
         {
             return AZStd::invoke(m_outer, AZStd::invoke(m_inner, AZStd::forward<Args>(args)...));
         }
         //
         template<class... Args>
         constexpr decltype(auto) operator()(Args&&... args) &&
-            noexcept(noexcept(AZStd::invoke(AZStd::move(m_outer),
-                AZStd::invoke(AZStd::move(m_inner), AZStd::forward<Args>(args)...))))
+            noexcept(noexcept(AZStd::invoke(declval<Outer>(),
+                AZStd::invoke(declval<Inner>(), AZStd::forward<Args>(args)...))))
         {
             return AZStd::invoke(AZStd::move(m_outer), AZStd::invoke(AZStd::move(m_inner), AZStd::forward<Args>(args)...));
         }
         template<class... Args>
         constexpr decltype(auto) operator()(Args&&... args) const&&
-            noexcept(noexcept(AZStd::invoke(AZStd::move(m_outer),
-                AZStd::invoke(AZStd::move(m_inner), AZStd::forward<Args>(args)...))))
+            noexcept(noexcept(AZStd::invoke(declval<Outer>(),
+                AZStd::invoke(declval<Inner>(), AZStd::forward<Args>(args)...))))
         {
             return AZStd::invoke(AZStd::move(m_outer), AZStd::invoke(AZStd::move(m_inner), AZStd::forward<Args>(args)...));
         }
diff --git a/Code/Framework/AzCore/AzCore/std/string/string_view.h b/Code/Framework/AzCore/AzCore/std/string/string_view.h
index af1482b05b..e9becea4b0 100644
--- a/Code/Framework/AzCore/AzCore/std/string/string_view.h
+++ b/Code/Framework/AzCore/AzCore/std/string/string_view.h
@@ -595,31 +595,44 @@ namespace AZStd
         static constexpr int_type not_eof(int_type c) noexcept { return c != eof() ? c : !eof(); }
     };
 
+    // string_view forward declaation
+    template <class Element, class Traits = AZStd::char_traits<Element>>
+    class basic_string_view;
+}
+
+namespace AZStd::Internal
+{
+    template <class Element, class Traits, class R, class = void>
+    struct has_operator_basic_string_view
+        : false_type
+    {};
+
+    template <class Element, class Traits, class R>
+    struct has_operator_basic_string_view<Element, Traits, R, enable_if_t<
+        bool(&decay_t<R>::operator basic_string_view<Element, Traits>)>>
+        : true_type
+    {};
+
+    // If the range has a traits_type element, it must match
+    template <class Element, class Traits, class R, class = void>
+    static constexpr bool range_trait_type_matches = true;
+    template <class Element, class Traits, class R>
+    inline constexpr bool range_trait_type_matches<Element, Traits, R,
+        enable_if_t<conjunction_v<
+        Internal::sfinae_trigger<typename remove_reference_t<R>::traits_type>,
+        bool_constant<!same_as<typename remove_reference_t<R>::traits_type, Traits>>
+        >>> = false;
+}
+namespace AZStd
+{
     /**
-     * Immutable string wrapper based on boost::const_string and std::string_view. When we operate on
+     * Immutable string wrapper based on std::string_view. When we operate on
      * const char* we don't know if this points to NULL terminated string or just a char array.
      * to have a clear distinction between them we provide this wrapper.
      */
-    template <class Element, class Traits = AZStd::char_traits<Element>>
+    template <class Element, class Traits>
     class basic_string_view
     {
-        template <class R, class = void>
-        static constexpr bool has_operator_basic_string_view = false;
-        template <class R>
-        static constexpr bool has_operator_basic_string_view<R, void_t<
-            decltype(declval<remove_cvref_t<R>>().operator basic_string_view<Element, Traits>())
-            >> = true;
-
-        // If the range has a traits_type element, it must match
-        template <class R, class = void>
-        static constexpr bool range_trait_type_matches = true;
-        template <class R>
-        static constexpr bool range_trait_type_matches<R,
-            enable_if_t<conjunction_v<
-            Internal::sfinae_trigger<typename remove_reference_t<R>::traits_type>,
-            bool_constant<!same_as<typename remove_reference_t<R>::traits_type, Traits>>
-            >>> = false;
-
     public:
         using traits_type = Traits;
         using value_type = Element;
@@ -674,8 +687,8 @@ namespace AZStd
             bool_constant<ranges::contiguous_range<R>>,
             bool_constant<ranges::sized_range<R>>,
             bool_constant<same_as<ranges::range_value_t<R>, value_type>>,
-            bool_constant<!has_operator_basic_string_view<R>>,
-            bool_constant<range_trait_type_matches<R>>
+            negation<Internal::has_operator_basic_string_view<Element, Traits, R>>,
+            bool_constant<Internal::range_trait_type_matches<Element, Traits, R>>
             >>>
         constexpr basic_string_view(R&& r)
             : m_begin(ranges::data(r))