'use strict';

let fastProto = null;

// Creates an object with permanently fast properties in V8. See Toon Verwaest's
// post https://medium.com/@tverwaes/setting-up-prototypes-in-v8-ec9c9491dfe2#5f62
// for more details. Use %HasFastProperties(object) and the Node.js flag
// --allow-natives-syntax to check whether an object has fast properties.
function FastObject(o) {
    // A prototype object will have "fast properties" enabled once it is checked
    // against the inline property cache of a function, e.g. fastProto.property:
    // https://github.com/v8/v8/blob/6.0.122/test/mjsunit/fast-prototype.js#L48-L63
    if (fastProto !== null && typeof fastProto.property) {
        const result = fastProto;
        fastProto = FastObject.prototype = null;
        return result;
    }
    fastProto = FastObject.prototype = o == null ? Object.create(null) : o;
    return new FastObject;
}

// Initialize the inline property cache of FastObject
FastObject();

module.exports = function toFastproperties(o) {
    return FastObject(o);
};