llvm-journey

commit df7a246c5f31680037e028b2d1ffa899c68a6a49
parent c2bf5312aab77745da9b24a4939bdd0ce5640766
Author: Mohammad-Reza Nabipoor <m.nabipoor@yahoo.com>
Date:   Fri, 28 Aug 2020 17:21:13 +0430

kaleidoscope_ast.hpp: Add cast func to ASTNode

By `cast` function the user can cast the polymorphic type `ASTNode`
to the concrete type inside the `ASTNode`.

Diffstat:
M
kaleidoscope_ast.hpp
 | 
18
++++++++++++++++++

1 file changed, 18 insertions(+), 0 deletions(-)
diff --git a/kaleidoscope_ast.hpp b/kaleidoscope_ast.hpp
@@ -129,6 +129,20 @@ public:
     return n.self_->node_type();
   }
 
+  template<typename T>
+  friend bool cast(const ASTNode& n, T& val)
+  {
+    if (!n.self_)
+      return false;
+
+    auto p = dynamic_cast<const Model<T>*>(n.self_.get());
+
+    if (p)
+      val = p->value_;
+
+    return p != nullptr;
+  }
+
   friend bool operator==(const ASTNode& x, const ASTNode& y)
   {
     assert(x.self_ != nullptr && y.self_ != nullptr);
@@ -184,6 +198,10 @@ private:
   std::shared_ptr<const Concept> self_;
 };
 
+template<typename T>
+bool
+cast(const ASTNode& n, T& val);
+
 struct Number
 {
   double value;