boolobject.c

/* Boolean type, a subtype of int */

#include "Python.h"
#include "pycore_object.h"      // _Py_FatalRefcountError()
#include "pycore_runtime.h"       // _Py_ID()

/* We define bool_repr to return "False" or "True" */

static PyObject *
bool_repr(PyObject *self)
{
    PyObject *res = self == Py_True ? &_Py_ID(True) : &_Py_ID(False);
    return Py_NewRef(res);
}

/* Function to return a bool from a C long */

PyObject *PyBool_FromLong(long ok)
{
    PyObject *result;

    if (ok)
        result = Py_True;
    else
        result = Py_False;
    Py_INCREF(result);
    return result;
}

/* We define bool_new to always return either Py_True or Py_False */

static PyObject *
bool_new(PyTypeObject *type, PyObject *args, PyObject *kwds)
{
    PyObject *x = Py_False;
    long ok;

    if (!_PyArg_NoKeywords("bool", kwds))
        return NULL;
    if (!PyArg_UnpackTuple(args, "bool", 0, 1, &x))
        return NULL;
    ok = PyObject_IsTrue(x);
    if (ok < 0)
        return NULL;
    return PyBool_FromLong(ok);
}

static PyObject *
bool_vectorcall(PyObject *type, PyObject * const*args,
                size_t nargsf, PyObject *kwnames)
{
    long ok = 0;
    if (!_PyArg_NoKwnames("bool", kwnames)) {
        return NULL;
    }

    Py_ssize_t nargs = PyVectorcall_NARGS(nargsf);
    if (!_PyArg_CheckPositional("bool", nargs, 0, 1)) {
        return NULL;
    }

    assert(PyType_Check(type));
    if (nargs) {
        ok = PyObject_IsTrue(args[0]);
        if (ok < 0) {
            return NULL;
        }
    }
    return PyBool_FromLong(ok);
}