Class cpp_function

include/pybind11/pybind11.h:304–1406

/// Wraps an arbitrary C++ function/method/lambda function/.. into a callable Python object
class cpp_function : public function {
public:
    cpp_function() = default;
    // NOLINTNEXTLINE(google-explicit-constructor)
    cpp_function(std::nullptr_t) {}
    cpp_function(std::nullptr_t, const is_setter &) {}

    /// Construct a cpp_function from a vanilla function pointer
    template <typename Return, typename... Args, typename... Extra>
    // NOLINTNEXTLINE(google-explicit-constructor)
    cpp_function(Return (*f)(Args...), const Extra &...extra) {
        initialize(f, f, extra...);
    }

    /// Construct a cpp_function from a lambda function (possibly with internal state)
    template <typename Func,
              typename... Extra,
              typename = detail::enable_if_t<detail::is_lambda<Func>::value>>
    // NOLINTNEXTLINE(google-explicit-constructor)
    cpp_function(Func &&f, const Extra &...extra) {
        initialize(
            std::forward<Func>(f), (detail::function_signature_t<Func> *) nullptr, extra...);
    }

    /// Construct a cpp_function from a class method (non-const, no ref-qualifier)
    template <typename Return, typename Class, typename... Arg, typename... Extra>
    // NOLINTNEXTLINE(google-explicit-constructor)
    cpp_function(Return (Class::*f)(Arg...), const Extra &...extra) {
        initialize(
            [f](Class *c, Arg... args) -> Return { return (c->*f)(std::forward<Arg>(args)...); },
            (Return (*)(Class *, Arg...)) nullptr,
            extra...);
    }

    /// Construct a cpp_function from a class method (non-const, lvalue ref-qualifier)
    /// A copy of the overload for non-const functions without explicit ref-qualifier
    /// but with an added `&`.
    template <typename Return, typename Class, typename... Arg, typename... Extra>
    // NOLINTNEXTLINE(google-explicit-constructor)
    cpp_function(Return (Class::*f)(Arg...) &, const Extra &...extra) {
        initialize(
            [f](Class *c, Arg... args) -> Return { return (c->*f)(std::forward<Arg>(args)...); },
            (Return (*)(Class *, Arg...)) nullptr,
            extra...);
    }

    /// Construct a cpp_function from a class method (const, no ref-qualifier)
    template <typename Return, typename Class, typename... Arg, typename... Extra>
    // NOLINTNEXTLINE(google-explicit-constructor)
    cpp_function(Return (Class::*f)(Arg...) const, const Extra &...extra) {
        initialize([f](const Class *c,
                       Arg... args) -> Return { return (c->*f)(std::forward<Arg>(args)...); },
                   (Return (*)(const Class *, Arg...)) nullptr,
                   extra...);
    }

    /// Construct a cpp_function from a class method (const, lvalue ref-qualifier)
    /// A copy of the overload for const functions without explicit ref-qualifier