Nodejs Addon - passing regex string to C++

Question

I am trying to figure out how to create a regular expression in C++. I want to turn a string passed from JavaScript to C++ into a regular expression.

I have this:

std::regex re;

  if (!args[1]->IsString()) {
    Nan::ThrowTypeError("Second argument to 'replace-line' must be a string regular expression.");
    return;
  }
  else{
    v8::String::Utf8Value regexin(args[1]->ToString());
    re(*regexin);
  }

but this fails to compile, with this error:

../hello.cpp: In function ‘void Method(const v8::FunctionCallbackInfo<v8::Value>&)’:
../hello.cpp:50:16: error: no match for call to ‘(regex_t {aka re_pattern_buffer}) (char*)’
     re(*regexin);

anybody know how I can declare/create a regex given this v8::String?

Answer 1

I am not sure about this, but maybe you have just declared regexin, but not initialized it? Have you tried doing V8... regexin = new V8... (args...)?