Gin: Add support for binding JS methods to C++ instance methods.

base/template_util.h

Index: base/template_util.h
diff --git a/base/template_util.h b/base/template_util.h
index 30572f1635857bc9a9c21da19500ca3ef90283ae..f4bf7461327bcb076bbe4bbf30bdd405f9bf3234 100644
--- a/base/template_util.h
+++ b/base/template_util.h
@@ -28,6 +28,39 @@ typedef integral_constant<bool, false> false_type;
 template <class T> struct is_pointer : false_type {};
 template <class T> struct is_pointer<T*> : true_type {};
 
+// Member function pointer detection up to four params. Add more as needed

[Jeffrey Yasskin, 2013/12/04 20:00:12]

There's a more complicated technique to detect arbitrary numbers of parameters
(http://stackoverflow.com/a/9008947/943619), but this is probably fine.

bind_internal also marks member-functions: 
https://code.google.com/p/chromium/codesearch/#chromium/src/base/bind_interna...
and
https://code.google.com/p/chromium/codesearch/#chromium/src/base/bind_helpers....
Let's ping awong to see if this should be exposed from Callback instead of
reinvented here.

+// below. This is built-in to C++ 11, and we can remove this when we switch.
+template<typename T>
+struct is_member_function_pointer : false_type {};
+
+template <typename R, typename Z>
+struct is_member_function_pointer<R(Z::*)()> : true_type {};
+template <typename R, typename Z>
+struct is_member_function_pointer<R(Z::*)() const> : true_type {};
+
+template <typename R, typename Z, typename A>
+struct is_member_function_pointer<R(Z::*)(A)> : true_type {};
+template <typename R, typename Z, typename A>
+struct is_member_function_pointer<R(Z::*)(A) const> : true_type {};
+
+template <typename R, typename Z, typename A, typename B>
+struct is_member_function_pointer<R(Z::*)(A, B)> : true_type {};
+template <typename R, typename Z, typename A, typename B>
+struct is_member_function_pointer<R(Z::*)(A, B) const> : true_type {};
+
+template <typename R, typename Z, typename A, typename B, typename C>
+struct is_member_function_pointer<R(Z::*)(A, B, C)> : true_type {};
+template <typename R, typename Z, typename A, typename B, typename C>
+struct is_member_function_pointer<R(Z::*)(A, B, C) const> : true_type {};
+
+template <typename R, typename Z, typename A, typename B, typename C,
+          typename D>
+struct is_member_function_pointer<R(Z::*)(A, B, C, D)> : true_type {};
+template <typename R, typename Z, typename A, typename B, typename C,
+          typename D>
+struct is_member_function_pointer<R(Z::*)(A, B, C, D) const> : true_type {};
+
+
 template <class T, class U> struct is_same : public false_type {};
 template <class T> struct is_same<T,T> : true_type {};