Bunch of small bug fixes (#2813)

* fix an error with addr_impl_ref assignment operator

Signed-off-by: nemerle <96597+nemerle@users.noreply.github.com>

* chrono duration unary '+' was missing a return

Signed-off-by: nemerle <96597+nemerle@users.noreply.github.com>

* HierarchyMenu constructor logic fix

Signed-off-by: nemerle <96597+nemerle@users.noreply.github.com>

* at least assert in case of invalid arguments to ring_buffer::insert

Signed-off-by: nemerle <96597+nemerle@users.noreply.github.com>

* EditorSettings using incorrect string_view::find result comparison

Signed-off-by: nemerle <96597+nemerle@users.noreply.github.com>

Code/Framework/AzCore/AzCore/std/chrono/types.h

@@ -211,7 +211,7 @@ namespace AZStd
             // 20.9.3.2, observer:
             constexpr rep count() const { return m_rep; }
             // 20.9.3.3, arithmetic:
-            constexpr duration operator+() const { *this; }
+            constexpr duration operator+() const { return *this; }
             constexpr duration operator-() const { return duration(-m_rep); }
             constexpr duration& operator++() { ++m_rep; return *this; }
             constexpr duration operator++(int) { return duration(m_rep++); }

Code/Framework/AzCore/AzCore/std/containers/ring_buffer.h

@@ -1056,7 +1056,7 @@ namespace AZStd
         inline void insert(const iterator& pos, ForwardIterator first, ForwardIterator last, const AZStd::forward_iterator_tag&)
         {
             size_type size = AZStd::distance(first, last);
-            AZSTD_CONTAINER_ASSERT(size >= 0, "AZStd::ring_buffer::insert - there are no elements to insert!");
+            AZSTD_CONTAINER_ASSERT(first > last, "AZStd::ring_buffer::insert - there are no elements to insert!");
             if (size == 0)
             {
                 return;

Code/Framework/AzCore/AzCore/std/utils.h

@@ -294,7 +294,7 @@ namespace AZStd
             T& m_v;
             constexpr addr_impl_ref(T& v)
                 : m_v(v) {}
-            constexpr addr_impl_ref& operator=(const addr_impl_ref& v) { m_v = v; }
+            constexpr addr_impl_ref& operator=(const addr_impl_ref& v) { m_v = v; return *this; }
             constexpr operator T& () const { return m_v; }
         };