Avoid symbol confliction on macOS (#78)

.bazelrc

@@ -1,5 +1,6 @@
 build --enable_platform_specific_config
-build:linux --cxxopt=-std=c++17
+build --features=-supports_dynamic_linker
+build --cxxopt=-std=c++17
 build:windows --cxxopt=-std:c++17
 
 try-import %workspace%/user.bazelrc

source/propagation_impl.cc

@@ -108,4 +108,12 @@ SpanContextExtensionImpl::SpanContextExtensionImpl(
   }
 }
 
+SpanContextPtr createSpanContext(std::string_view ctx) {
+  return std::make_unique<SpanContextImpl>(ctx);
+}
+
+SpanContextExtensionPtr createSpanContextExtension(std::string_view ctx) {
+  return std::make_unique<SpanContextExtensionImpl>(ctx);
+}
+
 }  // namespace cpp2sky

source/propagation_impl.h

@@ -62,12 +62,4 @@ class SpanContextExtensionImpl : public SpanContextExtension {
   TracingMode tracing_mode_ = TracingMode::Default;
 };
 
-SpanContextPtr createSpanContext(std::string_view ctx) {
-  return std::make_unique<SpanContextImpl>(ctx);
-}
-
-SpanContextExtensionPtr createSpanContextExtension(std::string_view ctx) {
-  return std::make_unique<SpanContextExtensionImpl>(ctx);
-}
-
 }  // namespace cpp2sky

source/tracer_impl.h

@@ -62,6 +62,4 @@ class TracerImpl : public Tracer {
   std::list<MatcherPtr> op_name_matchers_;
 };
 
-TracerPtr createInsecureGrpcTracer(TracerConfig& cfg);
-
 }  // namespace cpp2sky