ext/pybind11/tests/test_builtin_casters.py - public/gem5 - Git at Google

 # -*- coding: utf-8 -*-
 import pytest

 import env
 from pybind11_tests import IncType, UserType
 from pybind11_tests import builtin_casters as m


 def test_simple_string():
     assert m.string_roundtrip("const char *") == "const char *"


 def test_unicode_conversion():
     """Tests unicode conversion and error reporting."""
     assert m.good_utf8_string() == u"Say utf8‽ 🎂 𝐀"
     assert m.good_utf16_string() == u"b‽🎂𝐀z"
     assert m.good_utf32_string() == u"a𝐀🎂‽z"
     assert m.good_wchar_string() == u"a⸘𝐀z"
     if hasattr(m, "has_u8string"):
         assert m.good_utf8_u8string() == u"Say utf8‽ 🎂 𝐀"

     with pytest.raises(UnicodeDecodeError):
         m.bad_utf8_string()

     with pytest.raises(UnicodeDecodeError):
         m.bad_utf16_string()

     # These are provided only if they actually fail (they don't when 32-bit and under Python 2.7)
     if hasattr(m, "bad_utf32_string"):
         with pytest.raises(UnicodeDecodeError):
             m.bad_utf32_string()
     if hasattr(m, "bad_wchar_string"):
         with pytest.raises(UnicodeDecodeError):
             m.bad_wchar_string()
     if hasattr(m, "has_u8string"):
         with pytest.raises(UnicodeDecodeError):
             m.bad_utf8_u8string()

     assert m.u8_Z() == "Z"
     assert m.u8_eacute() == u"é"
     assert m.u16_ibang() == u"‽"
     assert m.u32_mathbfA() == u"𝐀"
     assert m.wchar_heart() == u"♥"
     if hasattr(m, "has_u8string"):
         assert m.u8_char8_Z() == "Z"


 def test_single_char_arguments():
     """Tests failures for passing invalid inputs to char-accepting functions"""

     def toobig_message(r):
         return "Character code point not in range({:#x})".format(r)

     toolong_message = "Expected a character, but multi-character string found"

     assert m.ord_char(u"a") == 0x61  # simple ASCII
     assert m.ord_char_lv(u"b") == 0x62
     assert (
         m.ord_char(u"é") == 0xE9
     )  # requires 2 bytes in utf-8, but can be stuffed in a char
     with pytest.raises(ValueError) as excinfo:
         assert m.ord_char(u"Ā") == 0x100  # requires 2 bytes, doesn't fit in a char
     assert str(excinfo.value) == toobig_message(0x100)
     with pytest.raises(ValueError) as excinfo:
         assert m.ord_char(u"ab")
     assert str(excinfo.value) == toolong_message

     assert m.ord_char16(u"a") == 0x61
     assert m.ord_char16(u"é") == 0xE9
     assert m.ord_char16_lv(u"ê") == 0xEA
     assert m.ord_char16(u"Ā") == 0x100
     assert m.ord_char16(u"‽") == 0x203D
     assert m.ord_char16(u"♥") == 0x2665
     assert m.ord_char16_lv(u"♡") == 0x2661
     with pytest.raises(ValueError) as excinfo:
         assert m.ord_char16(u"🎂") == 0x1F382  # requires surrogate pair
     assert str(excinfo.value) == toobig_message(0x10000)
     with pytest.raises(ValueError) as excinfo:
         assert m.ord_char16(u"aa")
     assert str(excinfo.value) == toolong_message

     assert m.ord_char32(u"a") == 0x61
     assert m.ord_char32(u"é") == 0xE9
     assert m.ord_char32(u"Ā") == 0x100
     assert m.ord_char32(u"‽") == 0x203D
     assert m.ord_char32(u"♥") == 0x2665
     assert m.ord_char32(u"🎂") == 0x1F382
     with pytest.raises(ValueError) as excinfo:
         assert m.ord_char32(u"aa")
     assert str(excinfo.value) == toolong_message

     assert m.ord_wchar(u"a") == 0x61
     assert m.ord_wchar(u"é") == 0xE9
     assert m.ord_wchar(u"Ā") == 0x100
     assert m.ord_wchar(u"‽") == 0x203D
     assert m.ord_wchar(u"♥") == 0x2665
     if m.wchar_size == 2:
         with pytest.raises(ValueError) as excinfo:
             assert m.ord_wchar(u"🎂") == 0x1F382  # requires surrogate pair
         assert str(excinfo.value) == toobig_message(0x10000)
     else:
         assert m.ord_wchar(u"🎂") == 0x1F382
     with pytest.raises(ValueError) as excinfo:
         assert m.ord_wchar(u"aa")
     assert str(excinfo.value) == toolong_message

     if hasattr(m, "has_u8string"):
         assert m.ord_char8(u"a") == 0x61  # simple ASCII
         assert m.ord_char8_lv(u"b") == 0x62
         assert (
             m.ord_char8(u"é") == 0xE9
         )  # requires 2 bytes in utf-8, but can be stuffed in a char
         with pytest.raises(ValueError) as excinfo:
             assert m.ord_char8(u"Ā") == 0x100  # requires 2 bytes, doesn't fit in a char
         assert str(excinfo.value) == toobig_message(0x100)
         with pytest.raises(ValueError) as excinfo:
             assert m.ord_char8(u"ab")
         assert str(excinfo.value) == toolong_message


 def test_bytes_to_string():
     """Tests the ability to pass bytes to C++ string-accepting functions.  Note that this is
     one-way: the only way to return bytes to Python is via the pybind11::bytes class."""
     # Issue #816

     def to_bytes(s):
         b = s if env.PY2 else s.encode("utf8")
         assert isinstance(b, bytes)
         return b

     assert m.strlen(to_bytes("hi")) == 2
     assert m.string_length(to_bytes("world")) == 5
     assert m.string_length(to_bytes("a\x00b")) == 3
     assert m.strlen(to_bytes("a\x00b")) == 1  # C-string limitation

     # passing in a utf8 encoded string should work
     assert m.string_length(u"💩".encode("utf8")) == 4


 @pytest.mark.skipif(not hasattr(m, "has_string_view"), reason="no <string_view>")
 def test_string_view(capture):
     """Tests support for C++17 string_view arguments and return values"""
     assert m.string_view_chars("Hi") == [72, 105]
     assert m.string_view_chars("Hi 🎂") == [72, 105, 32, 0xF0, 0x9F, 0x8E, 0x82]
     assert m.string_view16_chars(u"Hi 🎂") == [72, 105, 32, 0xD83C, 0xDF82]
     assert m.string_view32_chars(u"Hi 🎂") == [72, 105, 32, 127874]
     if hasattr(m, "has_u8string"):
         assert m.string_view8_chars("Hi") == [72, 105]
         assert m.string_view8_chars(u"Hi 🎂") == [72, 105, 32, 0xF0, 0x9F, 0x8E, 0x82]

     assert m.string_view_return() == u"utf8 secret 🎂"
     assert m.string_view16_return() == u"utf16 secret 🎂"
     assert m.string_view32_return() == u"utf32 secret 🎂"
     if hasattr(m, "has_u8string"):
         assert m.string_view8_return() == u"utf8 secret 🎂"

     with capture:
         m.string_view_print("Hi")
         m.string_view_print("utf8 🎂")
         m.string_view16_print(u"utf16 🎂")
         m.string_view32_print(u"utf32 🎂")
     assert (
         capture
         == u"""
         Hi 2
         utf8 🎂 9
         utf16 🎂 8
         utf32 🎂 7
     """
     )
     if hasattr(m, "has_u8string"):
         with capture:
             m.string_view8_print("Hi")
             m.string_view8_print(u"utf8 🎂")
         assert (
             capture
             == u"""
             Hi 2
             utf8 🎂 9
         """
         )

     with capture:
         m.string_view_print("Hi, ascii")
         m.string_view_print("Hi, utf8 🎂")
         m.string_view16_print(u"Hi, utf16 🎂")
         m.string_view32_print(u"Hi, utf32 🎂")
     assert (
         capture
         == u"""
         Hi, ascii 9
         Hi, utf8 🎂 13
         Hi, utf16 🎂 12
         Hi, utf32 🎂 11
     """
     )
     if hasattr(m, "has_u8string"):
         with capture:
             m.string_view8_print("Hi, ascii")
             m.string_view8_print(u"Hi, utf8 🎂")
         assert (
             capture
             == u"""
             Hi, ascii 9
             Hi, utf8 🎂 13
         """
         )


 def test_integer_casting():
     """Issue #929 - out-of-range integer values shouldn't be accepted"""
     assert m.i32_str(-1) == "-1"
     assert m.i64_str(-1) == "-1"
     assert m.i32_str(2000000000) == "2000000000"
     assert m.u32_str(2000000000) == "2000000000"
     if env.PY2:
         assert m.i32_str(long(-1)) == "-1"  # noqa: F821 undefined name 'long'
         assert m.i64_str(long(-1)) == "-1"  # noqa: F821 undefined name 'long'
         assert (
             m.i64_str(long(-999999999999))  # noqa: F821 undefined name 'long'
             == "-999999999999"
         )
         assert (
             m.u64_str(long(999999999999))  # noqa: F821 undefined name 'long'
             == "999999999999"
         )
     else:
         assert m.i64_str(-999999999999) == "-999999999999"
         assert m.u64_str(999999999999) == "999999999999"

     with pytest.raises(TypeError) as excinfo:
         m.u32_str(-1)
     assert "incompatible function arguments" in str(excinfo.value)
     with pytest.raises(TypeError) as excinfo:
         m.u64_str(-1)
     assert "incompatible function arguments" in str(excinfo.value)
     with pytest.raises(TypeError) as excinfo:
         m.i32_str(-3000000000)
     assert "incompatible function arguments" in str(excinfo.value)
     with pytest.raises(TypeError) as excinfo:
         m.i32_str(3000000000)
     assert "incompatible function arguments" in str(excinfo.value)

     if env.PY2:
         with pytest.raises(TypeError) as excinfo:
             m.u32_str(long(-1))  # noqa: F821 undefined name 'long'
         assert "incompatible function arguments" in str(excinfo.value)
         with pytest.raises(TypeError) as excinfo:
             m.u64_str(long(-1))  # noqa: F821 undefined name 'long'
         assert "incompatible function arguments" in str(excinfo.value)


 def test_int_convert():
     class Int(object):
         def __int__(self):
             return 42

     class NotInt(object):
         pass

     class Float(object):
         def __float__(self):
             return 41.99999

     class Index(object):
         def __index__(self):
             return 42

     class IntAndIndex(object):
         def __int__(self):
             return 42

         def __index__(self):
             return 0

     class RaisingTypeErrorOnIndex(object):
         def __index__(self):
             raise TypeError

         def __int__(self):
             return 42

     class RaisingValueErrorOnIndex(object):
         def __index__(self):
             raise ValueError

         def __int__(self):
             return 42

     convert, noconvert = m.int_passthrough, m.int_passthrough_noconvert

     def requires_conversion(v):
         pytest.raises(TypeError, noconvert, v)

     def cant_convert(v):
         pytest.raises(TypeError, convert, v)

     assert convert(7) == 7
     assert noconvert(7) == 7
     cant_convert(3.14159)
     # TODO: Avoid DeprecationWarning in `PyLong_AsLong` (and similar)
     if (3, 8) <= env.PY < (3, 10):
         with env.deprecated_call():
             assert convert(Int()) == 42
     else:
         assert convert(Int()) == 42
     requires_conversion(Int())
     cant_convert(NotInt())
     cant_convert(Float())

     # Before Python 3.8, `PyLong_AsLong` does not pick up on `obj.__index__`,
     # but pybind11 "backports" this behavior.
     assert convert(Index()) == 42
     assert noconvert(Index()) == 42
     assert convert(IntAndIndex()) == 0  # Fishy; `int(DoubleThought)` == 42
     assert noconvert(IntAndIndex()) == 0
     assert convert(RaisingTypeErrorOnIndex()) == 42
     requires_conversion(RaisingTypeErrorOnIndex())
     assert convert(RaisingValueErrorOnIndex()) == 42
     requires_conversion(RaisingValueErrorOnIndex())


 def test_numpy_int_convert():
     np = pytest.importorskip("numpy")

     convert, noconvert = m.int_passthrough, m.int_passthrough_noconvert

     def require_implicit(v):
         pytest.raises(TypeError, noconvert, v)

     # `np.intc` is an alias that corresponds to a C++ `int`
     assert convert(np.intc(42)) == 42
     assert noconvert(np.intc(42)) == 42

     # The implicit conversion from np.float32 is undesirable but currently accepted.
     # TODO: Avoid DeprecationWarning in `PyLong_AsLong` (and similar)
     if (3, 8) <= env.PY < (3, 10):
         with env.deprecated_call():
             assert convert(np.float32(3.14159)) == 3
     else:
         assert convert(np.float32(3.14159)) == 3
     require_implicit(np.float32(3.14159))


 def test_tuple(doc):
     """std::pair <-> tuple & std::tuple <-> tuple"""
     assert m.pair_passthrough((True, "test")) == ("test", True)
     assert m.tuple_passthrough((True, "test", 5)) == (5, "test", True)
     # Any sequence can be cast to a std::pair or std::tuple
     assert m.pair_passthrough([True, "test"]) == ("test", True)
     assert m.tuple_passthrough([True, "test", 5]) == (5, "test", True)
     assert m.empty_tuple() == ()

     assert (
         doc(m.pair_passthrough)
         == """
         pair_passthrough(arg0: Tuple[bool, str]) -> Tuple[str, bool]

         Return a pair in reversed order
     """
     )
     assert (
         doc(m.tuple_passthrough)
         == """
         tuple_passthrough(arg0: Tuple[bool, str, int]) -> Tuple[int, str, bool]

         Return a triple in reversed order
     """
     )

     assert m.rvalue_pair() == ("rvalue", "rvalue")
     assert m.lvalue_pair() == ("lvalue", "lvalue")
     assert m.rvalue_tuple() == ("rvalue", "rvalue", "rvalue")
     assert m.lvalue_tuple() == ("lvalue", "lvalue", "lvalue")
     assert m.rvalue_nested() == ("rvalue", ("rvalue", ("rvalue", "rvalue")))
     assert m.lvalue_nested() == ("lvalue", ("lvalue", ("lvalue", "lvalue")))

     assert m.int_string_pair() == (2, "items")


 def test_builtins_cast_return_none():
     """Casters produced with PYBIND11_TYPE_CASTER() should convert nullptr to None"""
     assert m.return_none_string() is None
     assert m.return_none_char() is None
     assert m.return_none_bool() is None
     assert m.return_none_int() is None
     assert m.return_none_float() is None
     assert m.return_none_pair() is None


 def test_none_deferred():
     """None passed as various argument types should defer to other overloads"""
     assert not m.defer_none_cstring("abc")
     assert m.defer_none_cstring(None)
     assert not m.defer_none_custom(UserType())
     assert m.defer_none_custom(None)
     assert m.nodefer_none_void(None)


 def test_void_caster():
     assert m.load_nullptr_t(None) is None
     assert m.cast_nullptr_t() is None


 def test_reference_wrapper():
     """std::reference_wrapper for builtin and user types"""
     assert m.refwrap_builtin(42) == 420
     assert m.refwrap_usertype(UserType(42)) == 42
     assert m.refwrap_usertype_const(UserType(42)) == 42

     with pytest.raises(TypeError) as excinfo:
         m.refwrap_builtin(None)
     assert "incompatible function arguments" in str(excinfo.value)

     with pytest.raises(TypeError) as excinfo:
         m.refwrap_usertype(None)
     assert "incompatible function arguments" in str(excinfo.value)

     assert m.refwrap_lvalue().value == 1
     assert m.refwrap_lvalue_const().value == 1

     a1 = m.refwrap_list(copy=True)
     a2 = m.refwrap_list(copy=True)
     assert [x.value for x in a1] == [2, 3]
     assert [x.value for x in a2] == [2, 3]
     assert not a1[0] is a2[0] and not a1[1] is a2[1]

     b1 = m.refwrap_list(copy=False)
     b2 = m.refwrap_list(copy=False)
     assert [x.value for x in b1] == [1, 2]
     assert [x.value for x in b2] == [1, 2]
     assert b1[0] is b2[0] and b1[1] is b2[1]

     assert m.refwrap_iiw(IncType(5)) == 5
     assert m.refwrap_call_iiw(IncType(10), m.refwrap_iiw) == [10, 10, 10, 10]


 def test_complex_cast():
     """std::complex casts"""
     assert m.complex_cast(1) == "1.0"
     assert m.complex_cast(2j) == "(0.0, 2.0)"


 def test_bool_caster():
     """Test bool caster implicit conversions."""
     convert, noconvert = m.bool_passthrough, m.bool_passthrough_noconvert

     def require_implicit(v):
         pytest.raises(TypeError, noconvert, v)

     def cant_convert(v):
         pytest.raises(TypeError, convert, v)

     # straight up bool
     assert convert(True) is True
     assert convert(False) is False
     assert noconvert(True) is True
     assert noconvert(False) is False

     # None requires implicit conversion
     require_implicit(None)
     assert convert(None) is False

     class A(object):
         def __init__(self, x):
             self.x = x

         def __nonzero__(self):
             return self.x

         def __bool__(self):
             return self.x

     class B(object):
         pass

     # Arbitrary objects are not accepted
     cant_convert(object())
     cant_convert(B())

     # Objects with __nonzero__ / __bool__ defined can be converted
     require_implicit(A(True))
     assert convert(A(True)) is True
     assert convert(A(False)) is False


 def test_numpy_bool():
     np = pytest.importorskip("numpy")

     convert, noconvert = m.bool_passthrough, m.bool_passthrough_noconvert

     def cant_convert(v):
         pytest.raises(TypeError, convert, v)

     # np.bool_ is not considered implicit
     assert convert(np.bool_(True)) is True
     assert convert(np.bool_(False)) is False
     assert noconvert(np.bool_(True)) is True
     assert noconvert(np.bool_(False)) is False
     cant_convert(np.zeros(2, dtype="int"))


 def test_int_long():
     """In Python 2, a C++ int should return a Python int rather than long
     if possible: longs are not always accepted where ints are used (such
     as the argument to sys.exit()). A C++ long long is always a Python
     long."""

     import sys

     must_be_long = type(getattr(sys, "maxint", 1) + 1)
     assert isinstance(m.int_cast(), int)
     assert isinstance(m.long_cast(), int)
     assert isinstance(m.longlong_cast(), must_be_long)


 def test_void_caster_2():
     assert m.test_void_caster()


 def test_const_ref_caster():
     """Verifies that const-ref is propagated through type_caster cast_op.
     The returned ConstRefCasted type is a minimal type that is constructed to
     reference the casting mode used.
     """
     x = False
     assert m.takes(x) == 1
     assert m.takes_move(x) == 1

     assert m.takes_ptr(x) == 3
     assert m.takes_ref(x) == 2
     assert m.takes_ref_wrap(x) == 2

     assert m.takes_const_ptr(x) == 5
     assert m.takes_const_ref(x) == 4
     assert m.takes_const_ref_wrap(x) == 4
	# -- coding: utf-8 --
	import pytest

	import env
	from pybind11_tests import IncType, UserType
	from pybind11_tests import builtin_casters as m


	def test_simple_string():
	assert m.string_roundtrip("const char ") == "const char "


	def test_unicode_conversion():
	"""Tests unicode conversion and error reporting."""
	assert m.good_utf8_string() == u"Say utf8‽ 🎂 𝐀"
	assert m.good_utf16_string() == u"b‽🎂𝐀z"
	assert m.good_utf32_string() == u"a𝐀🎂‽z"
	assert m.good_wchar_string() == u"a⸘𝐀z"
	if hasattr(m, "has_u8string"):
	assert m.good_utf8_u8string() == u"Say utf8‽ 🎂 𝐀"

	with pytest.raises(UnicodeDecodeError):
	m.bad_utf8_string()

	with pytest.raises(UnicodeDecodeError):
	m.bad_utf16_string()

	# These are provided only if they actually fail (they don't when 32-bit and under Python 2.7)
	if hasattr(m, "bad_utf32_string"):
	with pytest.raises(UnicodeDecodeError):
	m.bad_utf32_string()
	if hasattr(m, "bad_wchar_string"):
	with pytest.raises(UnicodeDecodeError):
	m.bad_wchar_string()
	if hasattr(m, "has_u8string"):
	with pytest.raises(UnicodeDecodeError):
	m.bad_utf8_u8string()

	assert m.u8_Z() == "Z"
	assert m.u8_eacute() == u"é"
	assert m.u16_ibang() == u"‽"
	assert m.u32_mathbfA() == u"𝐀"
	assert m.wchar_heart() == u"♥"
	if hasattr(m, "has_u8string"):
	assert m.u8_char8_Z() == "Z"


	def test_single_char_arguments():
	"""Tests failures for passing invalid inputs to char-accepting functions"""

	def toobig_message(r):
	return "Character code point not in range({:#x})".format(r)

	toolong_message = "Expected a character, but multi-character string found"

	assert m.ord_char(u"a") == 0x61 # simple ASCII
	assert m.ord_char_lv(u"b") == 0x62
	assert (
	m.ord_char(u"é") == 0xE9
	) # requires 2 bytes in utf-8, but can be stuffed in a char
	with pytest.raises(ValueError) as excinfo:
	assert m.ord_char(u"Ā") == 0x100 # requires 2 bytes, doesn't fit in a char
	assert str(excinfo.value) == toobig_message(0x100)
	with pytest.raises(ValueError) as excinfo:
	assert m.ord_char(u"ab")
	assert str(excinfo.value) == toolong_message

	assert m.ord_char16(u"a") == 0x61
	assert m.ord_char16(u"é") == 0xE9
	assert m.ord_char16_lv(u"ê") == 0xEA
	assert m.ord_char16(u"Ā") == 0x100
	assert m.ord_char16(u"‽") == 0x203D
	assert m.ord_char16(u"♥") == 0x2665
	assert m.ord_char16_lv(u"♡") == 0x2661
	with pytest.raises(ValueError) as excinfo:
	assert m.ord_char16(u"🎂") == 0x1F382 # requires surrogate pair
	assert str(excinfo.value) == toobig_message(0x10000)
	with pytest.raises(ValueError) as excinfo:
	assert m.ord_char16(u"aa")
	assert str(excinfo.value) == toolong_message

	assert m.ord_char32(u"a") == 0x61
	assert m.ord_char32(u"é") == 0xE9
	assert m.ord_char32(u"Ā") == 0x100
	assert m.ord_char32(u"‽") == 0x203D
	assert m.ord_char32(u"♥") == 0x2665
	assert m.ord_char32(u"🎂") == 0x1F382
	with pytest.raises(ValueError) as excinfo:
	assert m.ord_char32(u"aa")
	assert str(excinfo.value) == toolong_message

	assert m.ord_wchar(u"a") == 0x61
	assert m.ord_wchar(u"é") == 0xE9
	assert m.ord_wchar(u"Ā") == 0x100
	assert m.ord_wchar(u"‽") == 0x203D
	assert m.ord_wchar(u"♥") == 0x2665
	if m.wchar_size == 2:
	with pytest.raises(ValueError) as excinfo:
	assert m.ord_wchar(u"🎂") == 0x1F382 # requires surrogate pair
	assert str(excinfo.value) == toobig_message(0x10000)
	else:
	assert m.ord_wchar(u"🎂") == 0x1F382
	with pytest.raises(ValueError) as excinfo:
	assert m.ord_wchar(u"aa")
	assert str(excinfo.value) == toolong_message

	if hasattr(m, "has_u8string"):
	assert m.ord_char8(u"a") == 0x61 # simple ASCII
	assert m.ord_char8_lv(u"b") == 0x62
	assert (
	m.ord_char8(u"é") == 0xE9
	) # requires 2 bytes in utf-8, but can be stuffed in a char
	with pytest.raises(ValueError) as excinfo:
	assert m.ord_char8(u"Ā") == 0x100 # requires 2 bytes, doesn't fit in a char
	assert str(excinfo.value) == toobig_message(0x100)
	with pytest.raises(ValueError) as excinfo:
	assert m.ord_char8(u"ab")
	assert str(excinfo.value) == toolong_message


	def test_bytes_to_string():
	"""Tests the ability to pass bytes to C++ string-accepting functions. Note that this is
	one-way: the only way to return bytes to Python is via the pybind11::bytes class."""
	# Issue #816

	def to_bytes(s):
	b = s if env.PY2 else s.encode("utf8")
	assert isinstance(b, bytes)
	return b

	assert m.strlen(to_bytes("hi")) == 2
	assert m.string_length(to_bytes("world")) == 5
	assert m.string_length(to_bytes("a\x00b")) == 3
	assert m.strlen(to_bytes("a\x00b")) == 1 # C-string limitation

	# passing in a utf8 encoded string should work
	assert m.string_length(u"💩".encode("utf8")) == 4


	@pytest.mark.skipif(not hasattr(m, "has_string_view"), reason="no <string_view>")
	def test_string_view(capture):
	"""Tests support for C++17 string_view arguments and return values"""
	assert m.string_view_chars("Hi") == [72, 105]
	assert m.string_view_chars("Hi 🎂") == [72, 105, 32, 0xF0, 0x9F, 0x8E, 0x82]
	assert m.string_view16_chars(u"Hi 🎂") == [72, 105, 32, 0xD83C, 0xDF82]
	assert m.string_view32_chars(u"Hi 🎂") == [72, 105, 32, 127874]
	if hasattr(m, "has_u8string"):
	assert m.string_view8_chars("Hi") == [72, 105]
	assert m.string_view8_chars(u"Hi 🎂") == [72, 105, 32, 0xF0, 0x9F, 0x8E, 0x82]

	assert m.string_view_return() == u"utf8 secret 🎂"
	assert m.string_view16_return() == u"utf16 secret 🎂"
	assert m.string_view32_return() == u"utf32 secret 🎂"
	if hasattr(m, "has_u8string"):
	assert m.string_view8_return() == u"utf8 secret 🎂"

	with capture:
	m.string_view_print("Hi")
	m.string_view_print("utf8 🎂")
	m.string_view16_print(u"utf16 🎂")
	m.string_view32_print(u"utf32 🎂")
	assert (
	capture
	== u"""
	Hi 2
	utf8 🎂 9
	utf16 🎂 8
	utf32 🎂 7
	"""
	)
	if hasattr(m, "has_u8string"):
	with capture:
	m.string_view8_print("Hi")
	m.string_view8_print(u"utf8 🎂")
	assert (
	capture
	== u"""
	Hi 2
	utf8 🎂 9
	"""
	)

	with capture:
	m.string_view_print("Hi, ascii")
	m.string_view_print("Hi, utf8 🎂")
	m.string_view16_print(u"Hi, utf16 🎂")
	m.string_view32_print(u"Hi, utf32 🎂")
	assert (
	capture
	== u"""
	Hi, ascii 9
	Hi, utf8 🎂 13
	Hi, utf16 🎂 12
	Hi, utf32 🎂 11
	"""
	)
	if hasattr(m, "has_u8string"):
	with capture:
	m.string_view8_print("Hi, ascii")
	m.string_view8_print(u"Hi, utf8 🎂")
	assert (
	capture
	== u"""
	Hi, ascii 9
	Hi, utf8 🎂 13
	"""
	)


	def test_integer_casting():
	"""Issue #929 - out-of-range integer values shouldn't be accepted"""
	assert m.i32_str(-1) == "-1"
	assert m.i64_str(-1) == "-1"
	assert m.i32_str(2000000000) == "2000000000"
	assert m.u32_str(2000000000) == "2000000000"
	if env.PY2:
	assert m.i32_str(long(-1)) == "-1" # noqa: F821 undefined name 'long'
	assert m.i64_str(long(-1)) == "-1" # noqa: F821 undefined name 'long'
	assert (
	m.i64_str(long(-999999999999)) # noqa: F821 undefined name 'long'
	== "-999999999999"
	)
	assert (
	m.u64_str(long(999999999999)) # noqa: F821 undefined name 'long'
	== "999999999999"
	)
	else:
	assert m.i64_str(-999999999999) == "-999999999999"
	assert m.u64_str(999999999999) == "999999999999"

	with pytest.raises(TypeError) as excinfo:
	m.u32_str(-1)
	assert "incompatible function arguments" in str(excinfo.value)
	with pytest.raises(TypeError) as excinfo:
	m.u64_str(-1)
	assert "incompatible function arguments" in str(excinfo.value)
	with pytest.raises(TypeError) as excinfo:
	m.i32_str(-3000000000)
	assert "incompatible function arguments" in str(excinfo.value)
	with pytest.raises(TypeError) as excinfo:
	m.i32_str(3000000000)
	assert "incompatible function arguments" in str(excinfo.value)

	if env.PY2:
	with pytest.raises(TypeError) as excinfo:
	m.u32_str(long(-1)) # noqa: F821 undefined name 'long'
	assert "incompatible function arguments" in str(excinfo.value)
	with pytest.raises(TypeError) as excinfo:
	m.u64_str(long(-1)) # noqa: F821 undefined name 'long'
	assert "incompatible function arguments" in str(excinfo.value)


	def test_int_convert():
	class Int(object):
	def __int__(self):
	return 42

	class NotInt(object):
	pass

	class Float(object):
	def __float__(self):
	return 41.99999

	class Index(object):
	def __index__(self):
	return 42

	class IntAndIndex(object):
	def __int__(self):
	return 42

	def __index__(self):
	return 0

	class RaisingTypeErrorOnIndex(object):
	def __index__(self):
	raise TypeError

	def __int__(self):
	return 42

	class RaisingValueErrorOnIndex(object):
	def __index__(self):
	raise ValueError

	def __int__(self):
	return 42

	convert, noconvert = m.int_passthrough, m.int_passthrough_noconvert

	def requires_conversion(v):
	pytest.raises(TypeError, noconvert, v)

	def cant_convert(v):
	pytest.raises(TypeError, convert, v)

	assert convert(7) == 7
	assert noconvert(7) == 7
	cant_convert(3.14159)
	# TODO: Avoid DeprecationWarning in `PyLong_AsLong` (and similar)
	if (3, 8) <= env.PY < (3, 10):
	with env.deprecated_call():
	assert convert(Int()) == 42
	else:
	assert convert(Int()) == 42
	requires_conversion(Int())
	cant_convert(NotInt())
	cant_convert(Float())

	# Before Python 3.8, `PyLong_AsLong` does not pick up on `obj.__index__`,
	# but pybind11 "backports" this behavior.
	assert convert(Index()) == 42
	assert noconvert(Index()) == 42
	assert convert(IntAndIndex()) == 0 # Fishy; `int(DoubleThought)` == 42
	assert noconvert(IntAndIndex()) == 0
	assert convert(RaisingTypeErrorOnIndex()) == 42
	requires_conversion(RaisingTypeErrorOnIndex())
	assert convert(RaisingValueErrorOnIndex()) == 42
	requires_conversion(RaisingValueErrorOnIndex())


	def test_numpy_int_convert():
	np = pytest.importorskip("numpy")

	convert, noconvert = m.int_passthrough, m.int_passthrough_noconvert

	def require_implicit(v):
	pytest.raises(TypeError, noconvert, v)

	# `np.intc` is an alias that corresponds to a C++ `int`
	assert convert(np.intc(42)) == 42
	assert noconvert(np.intc(42)) == 42

	# The implicit conversion from np.float32 is undesirable but currently accepted.
	# TODO: Avoid DeprecationWarning in `PyLong_AsLong` (and similar)
	if (3, 8) <= env.PY < (3, 10):
	with env.deprecated_call():
	assert convert(np.float32(3.14159)) == 3
	else:
	assert convert(np.float32(3.14159)) == 3
	require_implicit(np.float32(3.14159))


	def test_tuple(doc):
	"""std::pair <-> tuple & std::tuple <-> tuple"""
	assert m.pair_passthrough((True, "test")) == ("test", True)
	assert m.tuple_passthrough((True, "test", 5)) == (5, "test", True)
	# Any sequence can be cast to a std::pair or std::tuple
	assert m.pair_passthrough([True, "test"]) == ("test", True)
	assert m.tuple_passthrough([True, "test", 5]) == (5, "test", True)
	assert m.empty_tuple() == ()

	assert (
	doc(m.pair_passthrough)
	== """
	pair_passthrough(arg0: Tuple[bool, str]) -> Tuple[str, bool]

	Return a pair in reversed order
	"""
	)
	assert (
	doc(m.tuple_passthrough)
	== """
	tuple_passthrough(arg0: Tuple[bool, str, int]) -> Tuple[int, str, bool]

	Return a triple in reversed order
	"""
	)

	assert m.rvalue_pair() == ("rvalue", "rvalue")
	assert m.lvalue_pair() == ("lvalue", "lvalue")
	assert m.rvalue_tuple() == ("rvalue", "rvalue", "rvalue")
	assert m.lvalue_tuple() == ("lvalue", "lvalue", "lvalue")
	assert m.rvalue_nested() == ("rvalue", ("rvalue", ("rvalue", "rvalue")))
	assert m.lvalue_nested() == ("lvalue", ("lvalue", ("lvalue", "lvalue")))

	assert m.int_string_pair() == (2, "items")


	def test_builtins_cast_return_none():
	"""Casters produced with PYBIND11_TYPE_CASTER() should convert nullptr to None"""
	assert m.return_none_string() is None
	assert m.return_none_char() is None
	assert m.return_none_bool() is None
	assert m.return_none_int() is None
	assert m.return_none_float() is None
	assert m.return_none_pair() is None


	def test_none_deferred():
	"""None passed as various argument types should defer to other overloads"""
	assert not m.defer_none_cstring("abc")
	assert m.defer_none_cstring(None)
	assert not m.defer_none_custom(UserType())
	assert m.defer_none_custom(None)
	assert m.nodefer_none_void(None)


	def test_void_caster():
	assert m.load_nullptr_t(None) is None
	assert m.cast_nullptr_t() is None


	def test_reference_wrapper():
	"""std::reference_wrapper for builtin and user types"""
	assert m.refwrap_builtin(42) == 420
	assert m.refwrap_usertype(UserType(42)) == 42
	assert m.refwrap_usertype_const(UserType(42)) == 42

	with pytest.raises(TypeError) as excinfo:
	m.refwrap_builtin(None)
	assert "incompatible function arguments" in str(excinfo.value)

	with pytest.raises(TypeError) as excinfo:
	m.refwrap_usertype(None)
	assert "incompatible function arguments" in str(excinfo.value)

	assert m.refwrap_lvalue().value == 1
	assert m.refwrap_lvalue_const().value == 1

	a1 = m.refwrap_list(copy=True)
	a2 = m.refwrap_list(copy=True)
	assert [x.value for x in a1] == [2, 3]
	assert [x.value for x in a2] == [2, 3]
	assert not a1[0] is a2[0] and not a1[1] is a2[1]

	b1 = m.refwrap_list(copy=False)
	b2 = m.refwrap_list(copy=False)
	assert [x.value for x in b1] == [1, 2]
	assert [x.value for x in b2] == [1, 2]
	assert b1[0] is b2[0] and b1[1] is b2[1]

	assert m.refwrap_iiw(IncType(5)) == 5
	assert m.refwrap_call_iiw(IncType(10), m.refwrap_iiw) == [10, 10, 10, 10]


	def test_complex_cast():
	"""std::complex casts"""
	assert m.complex_cast(1) == "1.0"
	assert m.complex_cast(2j) == "(0.0, 2.0)"


	def test_bool_caster():
	"""Test bool caster implicit conversions."""
	convert, noconvert = m.bool_passthrough, m.bool_passthrough_noconvert

	def require_implicit(v):
	pytest.raises(TypeError, noconvert, v)

	def cant_convert(v):
	pytest.raises(TypeError, convert, v)

	# straight up bool
	assert convert(True) is True
	assert convert(False) is False
	assert noconvert(True) is True
	assert noconvert(False) is False

	# None requires implicit conversion
	require_implicit(None)
	assert convert(None) is False

	class A(object):
	def __init__(self, x):
	self.x = x

	def __nonzero__(self):
	return self.x

	def __bool__(self):
	return self.x

	class B(object):
	pass

	# Arbitrary objects are not accepted
	cant_convert(object())
	cant_convert(B())

	# Objects with __nonzero__ / __bool__ defined can be converted
	require_implicit(A(True))
	assert convert(A(True)) is True
	assert convert(A(False)) is False


	def test_numpy_bool():
	np = pytest.importorskip("numpy")

	convert, noconvert = m.bool_passthrough, m.bool_passthrough_noconvert

	def cant_convert(v):
	pytest.raises(TypeError, convert, v)

	# np.bool_ is not considered implicit
	assert convert(np.bool_(True)) is True
	assert convert(np.bool_(False)) is False
	assert noconvert(np.bool_(True)) is True
	assert noconvert(np.bool_(False)) is False
	cant_convert(np.zeros(2, dtype="int"))


	def test_int_long():
	"""In Python 2, a C++ int should return a Python int rather than long
	if possible: longs are not always accepted where ints are used (such
	as the argument to sys.exit()). A C++ long long is always a Python
	long."""

	import sys

	must_be_long = type(getattr(sys, "maxint", 1) + 1)
	assert isinstance(m.int_cast(), int)
	assert isinstance(m.long_cast(), int)
	assert isinstance(m.longlong_cast(), must_be_long)


	def test_void_caster_2():
	assert m.test_void_caster()


	def test_const_ref_caster():
	"""Verifies that const-ref is propagated through type_caster cast_op.
	The returned ConstRefCasted type is a minimal type that is constructed to
	reference the casting mode used.
	"""
	x = False
	assert m.takes(x) == 1
	assert m.takes_move(x) == 1

	assert m.takes_ptr(x) == 3
	assert m.takes_ref(x) == 2
	assert m.takes_ref_wrap(x) == 2

	assert m.takes_const_ptr(x) == 5
	assert m.takes_const_ref(x) == 4
	assert m.takes_const_ref_wrap(x) == 4