Merge pull request #27 from lightstep/jmacd/c_string_support

Support C strings

Author: jmacd

src/c++11/lightstep/value.h

@@ -23,6 +23,7 @@ typedef mapbox::util::variant<bool,
 			      uint64_t,
 			      std::string,
 			      std::nullptr_t,
+			      const char*,
 			      mapbox::util::recursive_wrapper<Values>,
 			      mapbox::util::recursive_wrapper<Dictionary>> variant_type;
 
@@ -33,6 +34,9 @@ class Value : public variant_type {
 
   template <typename T>
   Value(T&& t) : variant_type(t) { }
+
+  template <int N>
+  Value(const char (&cstr)[N]) : variant_type(std::string(cstr)) { }
 };
 
 } // namespace lighstep

src/c++11/util.cc

@@ -82,6 +82,8 @@ struct KeyValueVisitor {
 
   void operator()(bool b) const { kv->set_bool_value(b); }
 
+  void operator()(const char* s) const { kv->set_string_value(s); }
+
   void operator()(const std::string &s) const { kv->set_string_value(s); }
 
   // More-or-less unsupported types:

test/c++11/flushproto_test.cc

@@ -69,6 +69,9 @@ int main() {
     auto recorder = tracer.impl()->recorder();
 
     auto span = lightstep::Tracer::Global().StartSpan("span/parent");
+    const char *v = "value";
+    span.SetTag("test1", v);
+    span.SetTag("test2", "value");
     span.SetBaggageItem("test", "baggage");
     auto parent = span.context();
     span.Finish();