Function GetOpGradFactory

tensorflow/core/framework/function.cc:1810–1813

typedef std::unordered_map<string, Creator> OpGradFactory;

OpGradFactory* GetOpGradFactory() {
  static OpGradFactory* factory = new OpGradFactory;
  return factory;
}

bool RegisterOp(const string& op, Creator func) {
  CHECK(GetOpGradFactory()->insert({op, func}).second)