base/bind.h.pump

$$ This is a pump file for generating file templates.  Pump is a python
$$ script that is part of the Google Test suite of utilities.  Description
$$ can be found here:
$$
$$ http://code.google.com/p/googletest/wiki/PumpManual
$$

$var MAX_ARITY = 6

// Copyright (c) 2011 The Chromium Authors. All rights reserved.
// Use of this source code is governed by a BSD-style license that can be
// found in the LICENSE file.

#ifndef BASE_BIND_H_
#define BASE_BIND_H_
#pragma once

#include "base/bind_internal.h"
#include "base/callback_internal.h"

// See base/callback.h for how to use these functions.
//
// IMPLEMENTATION NOTE
// Though Bind()'s result is meant to be stored in a Callback<> type, it
// cannot actually return the exact type without requiring a large amount
// of extra template specializations. The problem is that in order to
// discern the correct specialization of Callback<>, Bind would need to
// unwrap the function signature to determine the signature's arity, and
// whether or not it is a method.
//
// Each unique combination of (arity, function_type, num_prebound) where
// function_type is one of {function, method, const_method} would require
// one specialization.  We eventually have to do a similar number of
// specializations anyways in the implementation (see the FunctionTraitsN,
// classes).  However, it is avoidable in Bind if we return the result
// via an indirection like we do below.

namespace base {

$range BOUND 0..MAX_ARITY
$for BOUND [[
$range BOUND_ARG 1..BOUND

$if BOUND == 0 [[

template <typename Sig>
internal::InvokerStorageHolder<internal::InvokerStorage0<Sig> >
Bind(Sig f) {
  return internal::MakeInvokerStorageHolder(
      new internal::InvokerStorage0<Sig>(f));
}

]] $else [[

template <typename Sig, $for BOUND_ARG , [[typename P$(BOUND_ARG)]]>
internal::InvokerStorageHolder<internal::InvokerStorage$(BOUND)<Sig,
$for BOUND_ARG , [[P$(BOUND_ARG)]]> >
Bind(Sig f, $for BOUND_ARG , [[const P$(BOUND_ARG)& p$(BOUND_ARG)]]) {
  return internal::MakeInvokerStorageHolder(
      new internal::InvokerStorage$(BOUND)<Sig, [[]]
$for BOUND_ARG , [[P$(BOUND_ARG)]]>(
          f, $for BOUND_ARG , [[p$(BOUND_ARG)]]));
}

]]

]]  $$ for BOUND

}  // namespace base

#endif  // BASE_BIND_H_