pybind11/tests/test_class.py
Jason Rhinelander adbc8111bc Use stricter brace initialization
This updates the `py::init` constructors to only use brace
initialization for aggregate initiailization if there is no constructor
with the given arguments.

This, in particular, fixes the regression in #1247 where the presence of
a `std::initializer_list<T>` constructor started being invoked for
constructor invocations in 2.2 even when there was a specific
constructor of the desired type.

The added test case demonstrates: without this change, it fails to
compile because the `.def(py::init<std::vector<int>>())` constructor
tries to invoke the `T(std::initializer_list<std::vector<int>>)`
constructor rather than the `T(std::vector<int>)` constructor.

By only using `new T{...}`-style construction when a `T(...)`
constructor doesn't exist, we should bypass this by while still allowing
`py::init<...>` to be used for aggregate type initialization (since such
types, by definition, don't have a user-declared constructor).
2018-01-12 09:29:57 -04:00

269 lines
8.6 KiB
Python

import pytest
from pybind11_tests import class_ as m
from pybind11_tests import UserType, ConstructorStats
def test_repr():
# In Python 3.3+, repr() accesses __qualname__
assert "pybind11_type" in repr(type(UserType))
assert "UserType" in repr(UserType)
def test_instance(msg):
with pytest.raises(TypeError) as excinfo:
m.NoConstructor()
assert msg(excinfo.value) == "m.class_.NoConstructor: No constructor defined!"
instance = m.NoConstructor.new_instance()
cstats = ConstructorStats.get(m.NoConstructor)
assert cstats.alive() == 1
del instance
assert cstats.alive() == 0
def test_docstrings(doc):
assert doc(UserType) == "A `py::class_` type for testing"
assert UserType.__name__ == "UserType"
assert UserType.__module__ == "pybind11_tests"
assert UserType.get_value.__name__ == "get_value"
assert UserType.get_value.__module__ == "pybind11_tests"
assert doc(UserType.get_value) == """
get_value(self: m.UserType) -> int
Get value using a method
"""
assert doc(UserType.value) == "Get/set value using a property"
assert doc(m.NoConstructor.new_instance) == """
new_instance() -> m.class_.NoConstructor
Return an instance
"""
def test_qualname(doc):
"""Tests that a properly qualified name is set in __qualname__ (even in pre-3.3, where we
backport the attribute) and that generated docstrings properly use it and the module name"""
assert m.NestBase.__qualname__ == "NestBase"
assert m.NestBase.Nested.__qualname__ == "NestBase.Nested"
assert doc(m.NestBase.__init__) == """
__init__(self: m.class_.NestBase) -> None
"""
assert doc(m.NestBase.g) == """
g(self: m.class_.NestBase, arg0: m.class_.NestBase.Nested) -> None
"""
assert doc(m.NestBase.Nested.__init__) == """
__init__(self: m.class_.NestBase.Nested) -> None
"""
assert doc(m.NestBase.Nested.fn) == """
fn(self: m.class_.NestBase.Nested, arg0: int, arg1: m.class_.NestBase, arg2: m.class_.NestBase.Nested) -> None
""" # noqa: E501 line too long
assert doc(m.NestBase.Nested.fa) == """
fa(self: m.class_.NestBase.Nested, a: int, b: m.class_.NestBase, c: m.class_.NestBase.Nested) -> None
""" # noqa: E501 line too long
assert m.NestBase.__module__ == "pybind11_tests.class_"
assert m.NestBase.Nested.__module__ == "pybind11_tests.class_"
def test_inheritance(msg):
roger = m.Rabbit('Rabbit')
assert roger.name() + " is a " + roger.species() == "Rabbit is a parrot"
assert m.pet_name_species(roger) == "Rabbit is a parrot"
polly = m.Pet('Polly', 'parrot')
assert polly.name() + " is a " + polly.species() == "Polly is a parrot"
assert m.pet_name_species(polly) == "Polly is a parrot"
molly = m.Dog('Molly')
assert molly.name() + " is a " + molly.species() == "Molly is a dog"
assert m.pet_name_species(molly) == "Molly is a dog"
fred = m.Hamster('Fred')
assert fred.name() + " is a " + fred.species() == "Fred is a rodent"
assert m.dog_bark(molly) == "Woof!"
with pytest.raises(TypeError) as excinfo:
m.dog_bark(polly)
assert msg(excinfo.value) == """
dog_bark(): incompatible function arguments. The following argument types are supported:
1. (arg0: m.class_.Dog) -> str
Invoked with: <m.class_.Pet object at 0>
"""
with pytest.raises(TypeError) as excinfo:
m.Chimera("lion", "goat")
assert "No constructor defined!" in str(excinfo.value)
def test_automatic_upcasting():
assert type(m.return_class_1()).__name__ == "DerivedClass1"
assert type(m.return_class_2()).__name__ == "DerivedClass2"
assert type(m.return_none()).__name__ == "NoneType"
# Repeat these a few times in a random order to ensure no invalid caching is applied
assert type(m.return_class_n(1)).__name__ == "DerivedClass1"
assert type(m.return_class_n(2)).__name__ == "DerivedClass2"
assert type(m.return_class_n(0)).__name__ == "BaseClass"
assert type(m.return_class_n(2)).__name__ == "DerivedClass2"
assert type(m.return_class_n(2)).__name__ == "DerivedClass2"
assert type(m.return_class_n(0)).__name__ == "BaseClass"
assert type(m.return_class_n(1)).__name__ == "DerivedClass1"
def test_isinstance():
objects = [tuple(), dict(), m.Pet("Polly", "parrot")] + [m.Dog("Molly")] * 4
expected = (True, True, True, True, True, False, False)
assert m.check_instances(objects) == expected
def test_mismatched_holder():
import re
with pytest.raises(RuntimeError) as excinfo:
m.mismatched_holder_1()
assert re.match('generic_type: type ".*MismatchDerived1" does not have a non-default '
'holder type while its base ".*MismatchBase1" does', str(excinfo.value))
with pytest.raises(RuntimeError) as excinfo:
m.mismatched_holder_2()
assert re.match('generic_type: type ".*MismatchDerived2" has a non-default holder type '
'while its base ".*MismatchBase2" does not', str(excinfo.value))
def test_override_static():
"""#511: problem with inheritance + overwritten def_static"""
b = m.MyBase.make()
d1 = m.MyDerived.make2()
d2 = m.MyDerived.make()
assert isinstance(b, m.MyBase)
assert isinstance(d1, m.MyDerived)
assert isinstance(d2, m.MyDerived)
def test_implicit_conversion_life_support():
"""Ensure the lifetime of temporary objects created for implicit conversions"""
assert m.implicitly_convert_argument(UserType(5)) == 5
assert m.implicitly_convert_variable(UserType(5)) == 5
assert "outside a bound function" in m.implicitly_convert_variable_fail(UserType(5))
def test_operator_new_delete(capture):
"""Tests that class-specific operator new/delete functions are invoked"""
class SubAliased(m.AliasedHasOpNewDelSize):
pass
with capture:
a = m.HasOpNewDel()
b = m.HasOpNewDelSize()
d = m.HasOpNewDelBoth()
assert capture == """
A new 8
B new 4
D new 32
"""
sz_alias = str(m.AliasedHasOpNewDelSize.size_alias)
sz_noalias = str(m.AliasedHasOpNewDelSize.size_noalias)
with capture:
c = m.AliasedHasOpNewDelSize()
c2 = SubAliased()
assert capture == (
"C new " + sz_noalias + "\n" +
"C new " + sz_alias + "\n"
)
with capture:
del a
pytest.gc_collect()
del b
pytest.gc_collect()
del d
pytest.gc_collect()
assert capture == """
A delete
B delete 4
D delete
"""
with capture:
del c
pytest.gc_collect()
del c2
pytest.gc_collect()
assert capture == (
"C delete " + sz_noalias + "\n" +
"C delete " + sz_alias + "\n"
)
def test_bind_protected_functions():
"""Expose protected member functions to Python using a helper class"""
a = m.ProtectedA()
assert a.foo() == 42
b = m.ProtectedB()
assert b.foo() == 42
class C(m.ProtectedB):
def __init__(self):
m.ProtectedB.__init__(self)
def foo(self):
return 0
c = C()
assert c.foo() == 0
def test_brace_initialization():
""" Tests that simple POD classes can be constructed using C++11 brace initialization """
a = m.BraceInitialization(123, "test")
assert a.field1 == 123
assert a.field2 == "test"
# Tests that a non-simple class doesn't get brace initialization (if the
# class defines an initializer_list constructor, in particular, it would
# win over the expected constructor).
b = m.NoBraceInitialization([123, 456])
assert b.vec == [123, 456]
@pytest.unsupported_on_pypy
def test_class_refcount():
"""Instances must correctly increase/decrease the reference count of their types (#1029)"""
from sys import getrefcount
class PyDog(m.Dog):
pass
for cls in m.Dog, PyDog:
refcount_1 = getrefcount(cls)
molly = [cls("Molly") for _ in range(10)]
refcount_2 = getrefcount(cls)
del molly
pytest.gc_collect()
refcount_3 = getrefcount(cls)
assert refcount_1 == refcount_3
assert refcount_2 > refcount_1
def test_reentrant_implicit_conversion_failure(msg):
# ensure that there is no runaway reentrant implicit conversion (#1035)
with pytest.raises(TypeError) as excinfo:
m.BogusImplicitConversion(0)
assert msg(excinfo.value) == '''
__init__(): incompatible constructor arguments. The following argument types are supported:
1. m.class_.BogusImplicitConversion(arg0: m.class_.BogusImplicitConversion)
Invoked with: 0
'''