Add variant of Nan::New<v8::String> which takes a C++17 string_view

Author: robinchrist

nan.h

@@ -53,6 +53,10 @@
 
 #define NAN_HAS_CPLUSPLUS_17 (__cplusplus >= 201703L)
 
+#ifndef NAN_ENABLE_STRING_VIEW
+# define NAN_ENABLE_STRING_VIEW NAN_HAS_CPLUSPLUS_17
+#endif
+
 #include <uv.h>
 #include <node.h>
 #include <node_buffer.h>
@@ -74,6 +78,9 @@
 # include <string>
 # include <vector>
 #endif
+#if NAN_ENABLE_STRING_VIEW
+# include <string_view>
+#endif
 
 // uv helpers
 #ifdef UV_VERSION_MAJOR

nan_new.h

@@ -161,6 +161,9 @@ struct Factory<v8::String> : MaybeFactoryBase<v8::String> {
   static inline return_t New(const char *value, int length = -1);
   static inline return_t New(const uint16_t *value, int length = -1);
   static inline return_t New(std::string const& value);
+  #if NAN_ENABLE_STRING_VIEW
+  static inline return_t New(std::string_view value);
+  #endif
 
   static inline return_t New(v8::String::ExternalStringResource * value);
   static inline return_t New(ExternalOneByteStringResource * value);
@@ -289,6 +292,14 @@ New(double value) {
   return New<v8::Number>(value);
 }
 
+#if NAN_ENABLE_STRING_VIEW
+inline
+imp::Factory<v8::String>::return_t
+New(std::string_view value) {
+  return New<v8::String>(value.data(), value.length());
+}
+#endif
+
 inline
 imp::Factory<v8::String>::return_t
 New(std::string const& value) {  // NOLINT(build/include_what_you_use)