Question

I am viewing v8 header file, and got a problem again.

https://github.com/joyent/node/blob/master/deps/v8/include/v8.h#L1408-1414

typedef Handle<Value> (*AccessorGetter)(Local<String> property,
                                    const AccessorInfo& info);


typedef void (*AccessorSetter)(Local<String> property,
                           Local<Value> value,
                           const AccessorInfo& info);

I don’t know what this typedef use for?

Answer 1

The two type definitions create simple names for pointers to functions matching a given signature.

typedef Handle<Value> (*AccessorGetter)
    (Local<String> property,
     const AccessorInfo& info);

This defines a new type AccessorGetter that can be used to create variables that contain the address of a function with the signature

Handle<Value> SampleAccessorGetter
    (Local<String> property,
     const AccessorInfo& info)
{
    // ...
}

And it can be used in code such as:

int main ()
{
    // two variables that contain the address of `SampleAccessorGetter`.
    AccessorGetter f = &SampleAccessorGetter;
    AccessorGetter g = &SampleAccessorGetter;

    // these variables can be used to call the pointee function:
    f(...);
    g(...);
}