How much effort is implementing a constexpr object driven template system?

Clang Frontend
#1

Hi,

I started to think on a new kind of templating system in c++. Idea come from the AngularJS.com templating framework.

Here is a link for a longer description:
https://github.com/hun-nemethpeter/cpp-reflector-mini/blob/master/Proposal.md

here is an example:

// template part
template<typename T> [[meta::driver="EnumDriver(meta::class<T>) driver"]]
// EnumDriver is a constexpr class, that gets a compiler generated AST node
// in constructor parameter, through meta::class<T> in a type safe manner.
// (ex. enum declaration generates const EnumDecl*,
// and a class declaration generates const CXXRecordDecl*).
// driver instance name will be "driver", this is a normal C++ syntax
// members and methods of this object can be accessed with the following syntax:
// $driver.member$ or $driver.method(param1, param2, ...)$
void Json::readFrom(boost::optional<$driver.enumName$>& obj, const std::string& data)
{
  folly::fbstring jsonVal = folly::parseJson(data).asString();
  llvm::StringRef decoded(jsonVal.c_str(), jsonVal.length());
  obj = llvm::StringSwitch<$driver.enumName$>(decoded)
    // controlling directive meta::for, with the syntax of range base for
    // enumValueName will be a local variable of a CODT
    [[meta::for="(enumValueName:driver.enumValueNames)"]]
    .Case($enumValueName.asStr()$, $enumValueName$)
  ;
}

// driver part
class EnumDriver
{
  const EnumDecl* enumDecl;
  public:
    // used in [[std::driver="EnumDriver(meta::class<EVote>) driver"]]
    constexpr EnumDriver(const EnumDecl* enumDecl)
      : enumDecl(enumDecl)
    {
      std::string enumName = enumDecl->getNameAsString();
      for (auto it = enumDecl->enumerator_begin(); it != enumDecl->enumerator_end(); it++)
        enumNames.push_back((*it)->getName().data());
    }
    // used in [[meta::for(enumValueName:driver.enumValueNames)]]
    // meta::vector is a constexpr vector
    meta::vector<meta::id_string> enumValueNames;
    // used in $driver.enumName$
    // meta::id_string is a constexpr string that contains only valid C++ identifier
    // it has an asStr() that gives back a stringified string, so between "" signes
    meta::id_string enumName;
};

Is there any chance that I’m able to implement it in some day? How much effort implementing such a feature?

Peter