From fd908828948ceb80dc394fe63270dfd7ba5061d4 Mon Sep 17 00:00:00 2001
From: yhirose <yuji.hirose.bug@gmail.com>
Date: Tue, 3 Mar 2015 21:51:28 -0500
Subject: [PATCH] Improved SemanticValue interface.

---
 example/calc.cc  |  6 +++---
 example/calc2.cc |  6 +++---
 example/calc3.cc |  2 +-
 peglib.h         | 10 ++++++++++
 4 files changed, 17 insertions(+), 7 deletions(-)

diff --git a/example/calc.cc b/example/calc.cc
index 8c1ee4b..825e846 100644
--- a/example/calc.cc
+++ b/example/calc.cc
@@ -33,10 +33,10 @@ int main(int argc, const char** argv)
     const char* s = argv[1];
 
     auto reduce = [](const SemanticValues& sv) -> long {
-        auto result = sv[0].val.get<long>();
+        auto result = sv[0].get<long>();
         for (auto i = 1u; i < sv.size(); i += 2) {
-            auto num = sv[i + 1].val.get<long>();
-            auto ope = sv[i].val.get<char>();
+            auto num = sv[i + 1].get<long>();
+            auto ope = sv[i].get<char>();
             switch (ope) {
                 case '+': result += num; break;
                 case '-': result -= num; break;
diff --git a/example/calc2.cc b/example/calc2.cc
index d532bb8..04b0b45 100644
--- a/example/calc2.cc
+++ b/example/calc2.cc
@@ -32,10 +32,10 @@ int main(int argc, const char** argv)
     const char* s = argv[1];
 
     auto reduce = [](const SemanticValues& sv) -> long {
-        auto result = sv[0].val.get<long>();
+        auto result = sv[0].get<long>();
         for (auto i = 1u; i < sv.size(); i += 2) {
-            auto num = sv[i + 1].val.get<long>();
-            auto ope = sv[i].val.get<char>();
+            auto num = sv[i + 1].get<long>();
+            auto ope = sv[i].get<char>();
             switch (ope) {
                 case '+': result += num; break;
                 case '-': result -= num; break;
diff --git a/example/calc3.cc b/example/calc3.cc
index 6c69e2b..140c920 100644
--- a/example/calc3.cc
+++ b/example/calc3.cc
@@ -51,7 +51,7 @@ struct ast_ope : public ast_node
         return SemanticValues::reduce(
             sv.begin() + 1,
             sv.end(),
-            sv[0].val.get<shared_ptr<ast_node>>(),
+            sv[0].get<shared_ptr<ast_node>>(),
             [](shared_ptr<ast_node> r, SemanticValues::const_iterator i) {
                 auto ope = (i++)->val.get<char>();
                 auto nd = (i++)->val.get<shared_ptr<ast_node>>();
diff --git a/peglib.h b/peglib.h
index 70618b8..121b785 100644
--- a/peglib.h
+++ b/peglib.h
@@ -158,6 +158,16 @@ struct SemanticValue {
     SemanticValue(const any& _val, const char* _name, const char* _s, size_t _l)
         : val(_val), name(_name), s(_s), l(_l) {}
 
+    template <typename T>
+    T& get() {
+        return val.get<T>();
+    }
+
+    template <typename T>
+    const T& get() const {
+        return val.get<T>();
+    }
+
     any         val;
     const char* name;
     const char* s;