# dlib C++ Library - options.h

    /*
        pybind11/options.h: global settings that are configurable at runtime.

        Copyright (c) 2016 Wenzel Jakob <wenzel.jakob@epfl.ch>

        All rights reserved. Use of this source code is governed by a
        BSD-style license that can be found in the LICENSE file.
    */

    #pragma once

    #include "detail/common.h"

    NAMESPACE_BEGIN(PYBIND11_NAMESPACE)

    class options {
    public:

        // Default RAII constructor, which leaves settings as they currently are.
        options() : previous_state(global_state()) {}

        // Class is non-copyable.
        options(const options&) = delete;
        options& operator=(const options&) = delete;

        // Destructor, which restores settings that were in effect before.
        ~options() {
            global_state() = previous_state;
        }

        // Setter methods (affect the global state):

        options& disable_user_defined_docstrings() & { global_state().show_user_defined_docstrings = false; return *this; }

        options& enable_user_defined_docstrings() & { global_state().show_user_defined_docstrings = true; return *this; }

        options& disable_function_signatures() & { global_state().show_function_signatures = false; return *this; }

        options& enable_function_signatures() & { global_state().show_function_signatures = true; return *this; }

        // Getter methods (return the global state):

        static bool show_user_defined_docstrings() { return global_state().show_user_defined_docstrings; }

        static bool show_function_signatures() { return global_state().show_function_signatures; }

        // This type is not meant to be allocated on the heap.
        void* operator new(size_t) = delete;

    private:

        struct state {
            bool show_user_defined_docstrings = true;  //< Include user-supplied texts in docstrings.
            bool show_function_signatures = true;      //< Include auto-generated function signatures in docstrings.
        };

        static state &global_state() {
            static state instance;
            return instance;
        }

        state previous_state;
    };

    NAMESPACE_END(PYBIND11_NAMESPACE)