Introduce gdb::function_view
This commit adds a new function_view type. This type holds a non-owning reference to a callable. It is meant to be used as callback type of functions, instead of using the C-style pair of function pointer and 'void *data' arguments. function_view allows passing references to stateful function objects / lambdas with captures as callbacks efficiently, while function pointer + 'void *' does not. See the intro in the new function-view.h header for more. Unit tests included, put into a new gdb/unittests/ subdir. gdb/ChangeLog: 2017-02-23 Pedro Alves <palves@redhat.com> * Makefile.in (SUBDIR_UNITTESTS_SRCS, SUBDIR_UNITTESTS_OBS): New. (%.o) <unittests/%.c>: New pattern. * configure.ac ($development): Add $(SUBDIR_UNITTESTS_OBS) to CONFIG_OBS, and $(SUBDIR_UNITTESTS_SRCS) to CONFIG_SRCS. * common/function-view.h: New file. * unittests/function-view-selftests.c: New file. * configure: Regenerate.
This commit is contained in:
Pedro Alves
parent
1e9d41d49f
commit
07e253aa3b
@ -1,3 +1,13 @@
|
||||
2017-02-23 Pedro Alves <palves@redhat.com>
|
||||
|
||||
* Makefile.in (SUBDIR_UNITTESTS_SRCS, SUBDIR_UNITTESTS_OBS): New.
|
||||
(%.o) <unittests/%.c>: New pattern.
|
||||
* configure.ac ($development): Add $(SUBDIR_UNITTESTS_OBS) to
|
||||
CONFIG_OBS, and $(SUBDIR_UNITTESTS_SRCS) to CONFIG_SRCS.
|
||||
* common/function-view.h: New file.
|
||||
* unittests/function-view-selftests.c: New file.
|
||||
* configure: Regenerate.
|
||||
|
||||
2017-02-23 Simon Marchi <simon.marchi@ericsson.com>
|
||||
|
||||
* bsd-uthread.c (bsd_uthread_thread_alive): Use ptid instead of
|
||||
|
||||
@ -523,6 +523,12 @@ SUBDIR_PYTHON_DEPS =
|
||||
SUBDIR_PYTHON_LDFLAGS =
|
||||
SUBDIR_PYTHON_CFLAGS =
|
||||
|
||||
SUBDIR_UNITTESTS_SRCS = \
|
||||
unittests/function-view-selftests.c
|
||||
|
||||
SUBDIR_UNITTESTS_OBS = \
|
||||
function-view-selftests.o
|
||||
|
||||
# Opcodes currently live in one of two places. Either they are in the
|
||||
# opcode library, typically ../opcodes, or they are in a header file
|
||||
# in INCLUDE_DIR.
|
||||
@ -1909,6 +1915,10 @@ all: gdb$(EXEEXT) $(CONFIG_ALL)
|
||||
$(COMPILE) $<
|
||||
$(POSTCOMPILE)
|
||||
|
||||
%.o: ${srcdir}/unittests/%.c
|
||||
$(COMPILE) $<
|
||||
$(POSTCOMPILE)
|
||||
|
||||
# Specify an explicit rule for gdb/common/agent.c, to avoid a clash with the
|
||||
# object file generate by gdb/agent.c.
|
||||
common-agent.o: $(srcdir)/common/agent.c
|
||||
|
||||
355
gdb/common/function-view.h
Normal file
355
gdb/common/function-view.h
Normal file
@ -0,0 +1,355 @@
|
||||
/* Copyright (C) 2017 Free Software Foundation, Inc.
|
||||
|
||||
This file is part of GDB.
|
||||
|
||||
This program is free software; you can redistribute it and/or modify
|
||||
it under the terms of the GNU General Public License as published by
|
||||
the Free Software Foundation; either version 3 of the License, or
|
||||
(at your option) any later version.
|
||||
|
||||
This program is distributed in the hope that it will be useful,
|
||||
but WITHOUT ANY WARRANTY; without even the implied warranty of
|
||||
MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
|
||||
GNU General Public License for more details.
|
||||
|
||||
You should have received a copy of the GNU General Public License
|
||||
along with this program. If not, see <http://www.gnu.org/licenses/>. */
|
||||
|
||||
#ifndef COMMON_FUNCTION_VIEW_H
|
||||
#define COMMON_FUNCTION_VIEW_H
|
||||
|
||||
/* function_view is a polymorphic type-erasing wrapper class that
|
||||
encapsulates a non-owning reference to arbitrary callable objects.
|
||||
|
||||
A way to put it is that function_view is to std::function like
|
||||
std::string_view is to std::string. While std::function stores a
|
||||
type-erased callable object internally, function_view holds a
|
||||
type-erased reference to an external callable object.
|
||||
|
||||
This is meant to be used as callback type of a function that:
|
||||
|
||||
#1 - Takes a callback as parameter.
|
||||
|
||||
#2 - Wants to support arbitrary callable objects as callback type
|
||||
(e.g., stateful function objects, lambda closures, free
|
||||
functions).
|
||||
|
||||
#3 - Does not store the callback anywhere; instead the function
|
||||
just calls the callback directly or forwards it to some
|
||||
other function that calls it.
|
||||
|
||||
#4 - Can't be, or we don't want it to be, a template function
|
||||
with the callable type as template parameter. For example,
|
||||
when the callback is a parameter of a virtual member
|
||||
function, or when putting the function template in a header
|
||||
would expose too much implementation detail.
|
||||
|
||||
Note that the C-style "function pointer" + "void *data" callback
|
||||
parameter idiom fails requirement #2 above. Please don't add new
|
||||
uses of that idiom. I.e., something like this wouldn't work;
|
||||
|
||||
typedef bool (iterate_over_foos_cb) (foo *f, void *user_data),
|
||||
void iterate_over_foos (iterate_over_foos_cb *callback, void *user_data);
|
||||
|
||||
foo *find_foo_by_type (int type)
|
||||
{
|
||||
foo *found = nullptr;
|
||||
|
||||
iterate_over_foos ([&] (foo *f, void *data)
|
||||
{
|
||||
if (foo->type == type)
|
||||
{
|
||||
found = foo;
|
||||
return true; // stop iterating
|
||||
}
|
||||
return false; // continue iterating
|
||||
}, NULL);
|
||||
|
||||
return found;
|
||||
}
|
||||
|
||||
The above wouldn't compile, because lambdas with captures can't be
|
||||
implicitly converted to a function pointer (because a capture means
|
||||
some context data must be passed to the lambda somehow).
|
||||
|
||||
C++11 gave us std::function as type-erased wrapper around arbitrary
|
||||
callables, however, std::function is not an ideal fit for transient
|
||||
callbacks such as the use case above. For this use case, which is
|
||||
quite pervasive, a function_view is a better choice, because while
|
||||
function_view is light and does not require any heap allocation,
|
||||
std::function is a heavy-weight object with value semantics that
|
||||
generally requires a heap allocation on construction/assignment of
|
||||
the target callable. In addition, while it is possible to use
|
||||
std::function in such a way that avoids most of the overhead by
|
||||
making sure to only construct it with callables of types that fit
|
||||
std::function's small object optimization, such as function
|
||||
pointers and std::reference_wrapper callables, that is quite
|
||||
inconvenient in practice, because restricting to free-function
|
||||
callables would imply no state/capture/closure, which we need in
|
||||
most cases, and std::reference_wrapper implies remembering to use
|
||||
std::ref/std::cref where the callable is constructed, with the
|
||||
added inconvenience that std::ref/std::cref have deleted rvalue-ref
|
||||
overloads, meaning you can't use unnamed/temporary lambdas with
|
||||
them.
|
||||
|
||||
Note that because function_view is a non-owning view of a callable,
|
||||
care must be taken to ensure that the callable outlives the
|
||||
function_view that calls it. This is not really a problem for the
|
||||
use case function_view is intended for, such as passing a temporary
|
||||
function object / lambda to a function that accepts a callback,
|
||||
because in those cases, the temporary is guaranteed to be live
|
||||
until the called function returns.
|
||||
|
||||
Calling a function_view with no associated target is undefined,
|
||||
unlike with std::function, which throws std::bad_function_call.
|
||||
This is by design, to avoid the otherwise necessary NULL check in
|
||||
function_view::operator().
|
||||
|
||||
Since function_view objects are small (a pair of pointers), they
|
||||
should generally be passed around by value.
|
||||
|
||||
Usage:
|
||||
|
||||
Given this function that accepts a callback:
|
||||
|
||||
void
|
||||
iterate_over_foos (gdb::function_view<void (foo *)> callback)
|
||||
{
|
||||
for (auto &foo : foos)
|
||||
callback (&foo);
|
||||
}
|
||||
|
||||
you can call it like this, passing a lambda as callback:
|
||||
|
||||
iterate_over_foos ([&] (foo *f)
|
||||
{
|
||||
process_one_foo (f);
|
||||
});
|
||||
|
||||
or like this, passing a function object as callback:
|
||||
|
||||
struct function_object
|
||||
{
|
||||
void operator() (foo *f)
|
||||
{
|
||||
if (s->check ())
|
||||
process_one_foo (f);
|
||||
}
|
||||
|
||||
// some state
|
||||
state *s;
|
||||
};
|
||||
|
||||
state mystate;
|
||||
function_object matcher {&mystate};
|
||||
iterate_over_foos (matcher);
|
||||
|
||||
or like this, passing a function pointer as callback:
|
||||
|
||||
iterate_over_foos (process_one_foo);
|
||||
|
||||
You can find unit tests covering the whole API in
|
||||
unittests/function-view-selftests.c. */
|
||||
|
||||
namespace gdb {
|
||||
|
||||
namespace traits {
|
||||
/* A few trait helpers. */
|
||||
template<typename Predicate>
|
||||
struct Not : public std::integral_constant<bool, !Predicate::value>
|
||||
{};
|
||||
|
||||
template<typename...>
|
||||
struct Or;
|
||||
|
||||
template<>
|
||||
struct Or<> : public std::false_type
|
||||
{};
|
||||
|
||||
template<typename B1>
|
||||
struct Or<B1> : public B1
|
||||
{};
|
||||
|
||||
template<typename B1, typename B2>
|
||||
struct Or<B1, B2>
|
||||
: public std::conditional<B1::value, B1, B2>::type
|
||||
{};
|
||||
|
||||
template<typename B1,typename B2,typename B3, typename... Bn>
|
||||
struct Or<B1, B2, B3, Bn...>
|
||||
: public std::conditional<B1::value, B1, Or<B2, B3, Bn...>>::type
|
||||
{};
|
||||
} /* namespace traits */
|
||||
|
||||
namespace fv_detail {
|
||||
/* Bits shared by all function_view instantiations that do not depend
|
||||
on the template parameters. */
|
||||
|
||||
/* Storage for the erased callable. This is a union in order to be
|
||||
able to save both a function object (data) pointer or a function
|
||||
pointer without triggering undefined behavior. */
|
||||
union erased_callable
|
||||
{
|
||||
/* For function objects. */
|
||||
void *data;
|
||||
|
||||
/* For function pointers. */
|
||||
void (*fn) ();
|
||||
};
|
||||
|
||||
} /* namespace fv_detail */
|
||||
|
||||
/* Use partial specialization to get access to the callable's
|
||||
signature. */
|
||||
template<class Signature>
|
||||
struct function_view;
|
||||
|
||||
template<typename Res, typename... Args>
|
||||
class function_view<Res (Args...)>
|
||||
{
|
||||
template<typename From, typename To>
|
||||
using CompatibleReturnType
|
||||
= traits::Or<std::is_void<To>,
|
||||
std::is_same<From, To>,
|
||||
std::is_convertible<From, To>>;
|
||||
|
||||
/* True if Func can be called with Args, and either the result is
|
||||
Res, convertible to Res or Res is void. */
|
||||
template<typename Callable,
|
||||
typename Res2 = typename std::result_of<Callable &(Args...)>::type>
|
||||
struct IsCompatibleCallable : CompatibleReturnType<Res2, Res>
|
||||
{};
|
||||
|
||||
/* True if Callable is a function_view. Used to avoid hijacking the
|
||||
copy ctor. */
|
||||
template <typename Callable>
|
||||
struct IsFunctionView
|
||||
: std::is_same<function_view, typename std::decay<Callable>::type>
|
||||
{};
|
||||
|
||||
/* Helper to make SFINAE logic easier to read. */
|
||||
template<typename Condition>
|
||||
using Requires = typename std::enable_if<Condition::value, void>::type;
|
||||
|
||||
public:
|
||||
|
||||
/* NULL by default. */
|
||||
constexpr function_view () noexcept
|
||||
: m_erased_callable {},
|
||||
m_invoker {}
|
||||
{}
|
||||
|
||||
/* Default copy/assignment is fine. */
|
||||
function_view (const function_view &) = default;
|
||||
function_view &operator= (const function_view &) = default;
|
||||
|
||||
/* This is the main entry point. Use SFINAE to avoid hijacking the
|
||||
copy constructor and to ensure that the target type is
|
||||
compatible. */
|
||||
template
|
||||
<typename Callable,
|
||||
typename = Requires<traits::Not<IsFunctionView<Callable>>>,
|
||||
typename = Requires<IsCompatibleCallable<Callable>>>
|
||||
function_view (Callable &&callable) noexcept
|
||||
{
|
||||
bind (callable);
|
||||
}
|
||||
|
||||
/* Construct a NULL function_view. */
|
||||
constexpr function_view (std::nullptr_t) noexcept
|
||||
: m_erased_callable {},
|
||||
m_invoker {}
|
||||
{}
|
||||
|
||||
/* Clear a function_view. */
|
||||
function_view &operator= (std::nullptr_t) noexcept
|
||||
{
|
||||
m_invoker = nullptr;
|
||||
return *this;
|
||||
}
|
||||
|
||||
/* Return true if the wrapper has a target, false otherwise. Note
|
||||
we check M_INVOKER instead of M_ERASED_CALLABLE because we don't
|
||||
know which member of the union is active right now. */
|
||||
constexpr explicit operator bool () const noexcept
|
||||
{ return m_invoker != nullptr; }
|
||||
|
||||
/* Call the callable. */
|
||||
Res operator () (Args... args) const
|
||||
{ return m_invoker (m_erased_callable, std::forward<Args> (args)...); }
|
||||
|
||||
private:
|
||||
|
||||
/* Bind this function_view to a compatible function object
|
||||
reference. */
|
||||
template <typename Callable>
|
||||
void bind (Callable &callable) noexcept
|
||||
{
|
||||
m_erased_callable.data = (void *) std::addressof (callable);
|
||||
m_invoker = [] (fv_detail::erased_callable ecall, Args... args)
|
||||
noexcept (noexcept (callable (std::forward<Args> (args)...))) -> Res
|
||||
{
|
||||
auto &restored_callable = *static_cast<Callable *> (ecall.data);
|
||||
/* The explicit cast to Res avoids a compile error when Res is
|
||||
void and the callable returns non-void. */
|
||||
return (Res) restored_callable (std::forward<Args> (args)...);
|
||||
};
|
||||
}
|
||||
|
||||
/* Bind this function_view to a compatible function pointer.
|
||||
|
||||
Making this a separate function allows avoiding one indirection,
|
||||
by storing the function pointer directly in the storage, instead
|
||||
of a pointer to pointer. erased_callable is then a union in
|
||||
order to avoid storing a function pointer as a data pointer here,
|
||||
which would be undefined. */
|
||||
template<class Res2, typename... Args2>
|
||||
void bind (Res2 (*fn) (Args2...)) noexcept
|
||||
{
|
||||
m_erased_callable.fn = reinterpret_cast<void (*) ()> (fn);
|
||||
m_invoker = [] (fv_detail::erased_callable ecall, Args... args)
|
||||
noexcept (noexcept (fn (std::forward<Args> (args)...))) -> Res
|
||||
{
|
||||
auto restored_fn = reinterpret_cast<Res2 (*) (Args2...)> (ecall.fn);
|
||||
/* The explicit cast to Res avoids a compile error when Res is
|
||||
void and the callable returns non-void. */
|
||||
return (Res) restored_fn (std::forward<Args> (args)...);
|
||||
};
|
||||
}
|
||||
|
||||
/* Storage for the erased callable. */
|
||||
fv_detail::erased_callable m_erased_callable;
|
||||
|
||||
/* The invoker. This is set to a capture-less lambda by one of the
|
||||
'bind' overloads. The lambda restores the right type of the
|
||||
callable (which is passed as first argument), and forwards the
|
||||
args. */
|
||||
Res (*m_invoker) (fv_detail::erased_callable, Args...);
|
||||
};
|
||||
|
||||
/* Allow comparison with NULL. Defer the work to the in-class
|
||||
operator bool implementation. */
|
||||
|
||||
template<typename Res, typename... Args>
|
||||
constexpr inline bool
|
||||
operator== (const function_view<Res (Args...)> &f, std::nullptr_t) noexcept
|
||||
{ return !static_cast<bool> (f); }
|
||||
|
||||
template<typename Res, typename... Args>
|
||||
constexpr inline bool
|
||||
operator== (std::nullptr_t, const function_view<Res (Args...)> &f) noexcept
|
||||
{ return !static_cast<bool> (f); }
|
||||
|
||||
template<typename Res, typename... Args>
|
||||
constexpr inline bool
|
||||
operator!= (const function_view<Res (Args...)> &f, std::nullptr_t) noexcept
|
||||
{ return static_cast<bool> (f); }
|
||||
|
||||
template<typename Res, typename... Args>
|
||||
constexpr inline bool
|
||||
operator!= (std::nullptr_t, const function_view<Res (Args...)> &f) noexcept
|
||||
{ return static_cast<bool> (f); }
|
||||
|
||||
} /* namespace gdb */
|
||||
|
||||
#endif
|
||||
2
gdb/configure
vendored
2
gdb/configure
vendored
@ -17410,6 +17410,8 @@ if $development; then
|
||||
|
||||
$as_echo "#define GDB_SELF_TEST 1" >>confdefs.h
|
||||
|
||||
CONFIG_OBS="$CONFIG_OBS \$(SUBDIR_UNITTESTS_OBS)"
|
||||
CONFIG_SRCS="$CONFIG_SRCS \$(SUBDIR_UNITTESTS_SRCS)"
|
||||
fi
|
||||
|
||||
|
||||
|
||||
@ -2350,6 +2350,8 @@ AC_DEFINE(GDB_DEFAULT_HOST_CHARSET, "UTF-8",
|
||||
if $development; then
|
||||
AC_DEFINE(GDB_SELF_TEST, 1,
|
||||
[Define if self-testing features should be enabled])
|
||||
CONFIG_OBS="$CONFIG_OBS \$(SUBDIR_UNITTESTS_OBS)"
|
||||
CONFIG_SRCS="$CONFIG_SRCS \$(SUBDIR_UNITTESTS_SRCS)"
|
||||
fi
|
||||
|
||||
GDB_AC_TRANSFORM([gdb], [GDB_TRANSFORM_NAME])
|
||||
|
||||
178
gdb/unittests/function-view-selftests.c
Normal file
178
gdb/unittests/function-view-selftests.c
Normal file
@ -0,0 +1,178 @@
|
||||
/* Self tests for function_view for GDB, the GNU debugger.
|
||||
|
||||
Copyright (C) 2017 Free Software Foundation, Inc.
|
||||
|
||||
This file is part of GDB.
|
||||
|
||||
This program is free software; you can redistribute it and/or modify
|
||||
it under the terms of the GNU General Public License as published by
|
||||
the Free Software Foundation; either version 3 of the License, or
|
||||
(at your option) any later version.
|
||||
|
||||
This program is distributed in the hope that it will be useful,
|
||||
but WITHOUT ANY WARRANTY; without even the implied warranty of
|
||||
MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
|
||||
GNU General Public License for more details.
|
||||
|
||||
You should have received a copy of the GNU General Public License
|
||||
along with this program. If not, see <http://www.gnu.org/licenses/>. */
|
||||
|
||||
#include "defs.h"
|
||||
#include "selftest.h"
|
||||
#include "common/function-view.h"
|
||||
|
||||
namespace selftests {
|
||||
namespace function_view {
|
||||
|
||||
static int
|
||||
plus_one_fn_int (int val)
|
||||
{
|
||||
return ++val;
|
||||
}
|
||||
|
||||
static short
|
||||
plus_one_fn_short (short val)
|
||||
{
|
||||
return ++val;
|
||||
}
|
||||
|
||||
static int
|
||||
call_callback_int (int val, gdb::function_view <int (int)> callback)
|
||||
{
|
||||
return callback (val);
|
||||
}
|
||||
|
||||
static void
|
||||
call_callback_void (int val, gdb::function_view <void (int)> callback)
|
||||
{
|
||||
callback (val);
|
||||
}
|
||||
|
||||
struct plus_one_int_func_obj
|
||||
{
|
||||
int operator () (int val)
|
||||
{
|
||||
++call_count;
|
||||
return ++val;
|
||||
}
|
||||
|
||||
/* Number of times called. */
|
||||
int call_count = 0;
|
||||
};
|
||||
|
||||
static void
|
||||
run_tests ()
|
||||
{
|
||||
/* A simple lambda. */
|
||||
auto plus_one_lambda = [] (int val) { return ++val; };
|
||||
|
||||
/* A function_view that references the lambda. */
|
||||
gdb::function_view<int (int)> plus_one_func_view (plus_one_lambda);
|
||||
|
||||
/* Check calling the lambda directly. */
|
||||
SELF_CHECK (plus_one_lambda (0) == 1);
|
||||
SELF_CHECK (plus_one_lambda (1) == 2);
|
||||
|
||||
/* Check calling lambda via the view. */
|
||||
SELF_CHECK (plus_one_func_view (2) == 3);
|
||||
SELF_CHECK (plus_one_func_view (3) == 4);
|
||||
|
||||
/* Check calling a function that takes a function_view as argument,
|
||||
by value. Pass a lambda, making sure a function_view is properly
|
||||
constructed implicitly. */
|
||||
SELF_CHECK (call_callback_int (1, [] (int val)
|
||||
{
|
||||
return val + 2;
|
||||
}) == 3);
|
||||
|
||||
/* Same, passing a named/lvalue lambda. */
|
||||
SELF_CHECK (call_callback_int (1, plus_one_lambda) == 2);
|
||||
/* Same, passing a named/lvalue function_view (should copy). */
|
||||
SELF_CHECK (call_callback_int (1, plus_one_func_view) == 2);
|
||||
|
||||
/* Check constructing a function view over a function-object
|
||||
callable, and calling it. */
|
||||
plus_one_int_func_obj func_obj;
|
||||
SELF_CHECK (func_obj (0) == 1);
|
||||
SELF_CHECK (call_callback_int (1, func_obj) == 2);
|
||||
/* Check that the callable was referenced, not copied. */
|
||||
SELF_CHECK (func_obj.call_count == 2);
|
||||
|
||||
/* Check constructing a function_view over a free-function callable,
|
||||
and calling it. */
|
||||
SELF_CHECK (call_callback_int (1, plus_one_fn_int) == 2);
|
||||
|
||||
/* Check calling a function with a
|
||||
compatible-but-not-exactly-the-same prototype. */
|
||||
SELF_CHECK (call_callback_int (1, [] (short val) -> short
|
||||
{
|
||||
return val + 2;
|
||||
}) == 3);
|
||||
/* Same, but passing a function pointer. */
|
||||
SELF_CHECK (call_callback_int (1, plus_one_fn_short) == 2);
|
||||
|
||||
/* Like std::function, a function_view that expects a void return
|
||||
can reference callables with non-void return type. The result is
|
||||
simply discarded. Check a lambda, function object and a function
|
||||
pointer. */
|
||||
call_callback_void (1, [] (int val) -> int
|
||||
{
|
||||
return val + 2;
|
||||
});
|
||||
call_callback_void (1, func_obj);
|
||||
call_callback_void (1, plus_one_fn_int);
|
||||
|
||||
/* Check that the main ctor doesn't hijack the copy ctor. */
|
||||
auto plus_one_func_view2 (plus_one_func_view);
|
||||
auto plus_one_func_view3 (plus_one_func_view2);
|
||||
static_assert (std::is_same<decltype (plus_one_func_view),
|
||||
decltype (plus_one_func_view2)>::value, "");
|
||||
static_assert (std::is_same<decltype (plus_one_func_view),
|
||||
decltype (plus_one_func_view3)>::value, "");
|
||||
|
||||
SELF_CHECK (plus_one_func_view3 (1) == 2);
|
||||
|
||||
/* Likewise, but propagate a NULL callable. If this calls the main
|
||||
function_view ctor instead of the copy ctor by mistake, then
|
||||
null_func_2 ends up non-NULL (because it'd instead reference
|
||||
null_func_1 as just another callable). */
|
||||
constexpr gdb::function_view<int (int)> null_func_view_1 = nullptr;
|
||||
constexpr auto null_func_view_2 (null_func_view_1);
|
||||
|
||||
/* While at it, check whether the function_view is bound using
|
||||
various forms, op==, op!= and op bool. */
|
||||
|
||||
/* op== */
|
||||
static_assert (null_func_view_2 == nullptr, "");
|
||||
static_assert (nullptr == null_func_view_2, "");
|
||||
static_assert (null_func_view_2 == NULL, "");
|
||||
static_assert (NULL == null_func_view_2, "");
|
||||
|
||||
/* op!= */
|
||||
static_assert (!(null_func_view_2 != nullptr), "");
|
||||
static_assert (!(nullptr != null_func_view_2), "");
|
||||
static_assert (!(null_func_view_2 != NULL), "");
|
||||
static_assert (!(NULL != null_func_view_2), "");
|
||||
|
||||
/* op bool */
|
||||
static_assert (!null_func_view_2, "");
|
||||
|
||||
/* Check the nullptr_t ctor. */
|
||||
constexpr gdb::function_view<int (int)> check_ctor_nullptr (nullptr);
|
||||
static_assert (!check_ctor_nullptr, "");
|
||||
|
||||
/* Check the nullptr_t op= */
|
||||
gdb::function_view<int (int)> check_op_eq_null (plus_one_fn_int);
|
||||
SELF_CHECK (check_op_eq_null);
|
||||
check_op_eq_null = nullptr;
|
||||
SELF_CHECK (!check_op_eq_null);
|
||||
}
|
||||
|
||||
} /* namespace function_view */
|
||||
} /* namespace selftests */
|
||||
|
||||
void
|
||||
_initialize_function_view_selftests ()
|
||||
{
|
||||
register_self_test (selftests::function_view::run_tests);
|
||||
}
|
||||
Loading…
Reference in New Issue
Block a user