Allow using a type as both a base type and a member type, closes #333

`store_as_base<Name, T>` should hold its `T` by value, not by private base... I should know better than use private inheritance :)

While I was trying an alternate solution (that I then backed out), I created a `cpp2::contains` function... now it isn't being used, but will likely be useful so I'll leave it in

Author: hsutter

include/cpp2util.h

@@ -641,14 +641,17 @@ class out {
 
 
 template<String Name, typename T>
-struct store_as_base : private T
+class store_as_base
 {
-    store_as_base( T const& t    ) : T{t}                  { }
-    store_as_base( T     && t    ) : T{std::move(t)}       { }
-    store_as_base( auto  && args ) : T{CPP2_FORWARD(args)} { }
+    T value;
 
-    auto value__()       -> T      & { return *this; }
-    auto value__() const -> T const& { return *this; }
+public:
+    store_as_base( T const& t    ) : value{t}                  { }
+    store_as_base( T     && t    ) : value{std::move(t)}       { }
+    store_as_base( auto  && args ) : value{CPP2_FORWARD(args)} { }
+
+    auto value__()       -> T      & { return value; }
+    auto value__() const -> T const& { return value; }
 };
 
 

regression-tests/test-results/pure2-ufcs-member-access-and-chaining.cpp

@@ -47,7 +47,7 @@ extern int y;
 
     CPP2_UFCS_0(ufcs, get_i(fun()));
 
-    auto res {CPP2_UFCS_0(ufcs, 42)}; 
+    auto res {CPP2_UFCS_0(ufcs, (42))}; 
 
     CPP2_UFCS_0(ufcs, (std::move(j).i));
 }

source/common.h

@@ -487,6 +487,21 @@ auto starts_with(
 }
 
 
+auto contains(
+    auto const& range,
+    auto const& value
+)
+    -> bool
+{
+    return std::find(
+        range.begin(),
+        range.end(),
+        value
+        )
+        != range.end();
+}
+
+
 //-----------------------------------------------------------------------
 //
 //  Command line handling