Apply function on each value of parameter pack and check return values
-3
Have this piece of working code:
template < class... Objects >
static void callNotifyOnPointerObjects ( Objects&&... objects )
{
int arr = { 0, ( static_cast< void > ( objects->Notify () ), 0 )... };
static_cast< void > ( arr );
}
objects->Notify() return value is bool
How can I put into bool array return values coming from execution of objects->Notify() and check if all values are true:
template < class... Objects >
static bool callNotifyOnPointerObjects ( Objects&&... objects )
{
// Put in this array return values from objects->Notify () execution
bool rc [sizeof...(objects)] = {false};
int arr = { 0, ( static_cast< void > ( objects->Notify () ), 0 )... };
static_cast< void > ( arr );
// check if all values in rc == true and return true or false
// return result;
}
c++ c++11 variadic-templates
edited Nov 21 '18 at 12:52
Swordfish
1
asked Nov 21 '18 at 11:51
RomaRoma
184
add a comment |
-3
Have this piece of working code:
template < class... Objects >
static void callNotifyOnPointerObjects ( Objects&&... objects )
{
int arr = { 0, ( static_cast< void > ( objects->Notify () ), 0 )... };
static_cast< void > ( arr );
}
objects->Notify() return value is bool
How can I put into bool array return values coming from execution of objects->Notify() and check if all values are true:
template < class... Objects >
static bool callNotifyOnPointerObjects ( Objects&&... objects )
{
// Put in this array return values from objects->Notify () execution
bool rc [sizeof...(objects)] = {false};
int arr = { 0, ( static_cast< void > ( objects->Notify () ), 0 )... };
static_cast< void > ( arr );
// check if all values in rc == true and return true or false
// return result;
}
c++ c++11 variadic-templates
edited Nov 21 '18 at 12:52
Swordfish
1
asked Nov 21 '18 at 11:51
RomaRoma
184
1
Trystd::all_of.
– n.m.
Nov 21 '18 at 12:26
add a comment |
-3
-3
-3
Have this piece of working code:
template < class... Objects >
static void callNotifyOnPointerObjects ( Objects&&... objects )
{
int arr = { 0, ( static_cast< void > ( objects->Notify () ), 0 )... };
static_cast< void > ( arr );
}
objects->Notify() return value is bool
How can I put into bool array return values coming from execution of objects->Notify() and check if all values are true:
template < class... Objects >
static bool callNotifyOnPointerObjects ( Objects&&... objects )
{
// Put in this array return values from objects->Notify () execution
bool rc [sizeof...(objects)] = {false};
int arr = { 0, ( static_cast< void > ( objects->Notify () ), 0 )... };
static_cast< void > ( arr );
// check if all values in rc == true and return true or false
// return result;
}
c++ c++11 variadic-templates
edited Nov 21 '18 at 12:52
Swordfish
1
asked Nov 21 '18 at 11:51
RomaRoma
184
Have this piece of working code:
template < class... Objects >
static void callNotifyOnPointerObjects ( Objects&&... objects )
{
int arr = { 0, ( static_cast< void > ( objects->Notify () ), 0 )... };
static_cast< void > ( arr );
}
objects->Notify() return value is bool
How can I put into bool array return values coming from execution of objects->Notify() and check if all values are true:
template < class... Objects >
static bool callNotifyOnPointerObjects ( Objects&&... objects )
{
// Put in this array return values from objects->Notify () execution
bool rc [sizeof...(objects)] = {false};
int arr = { 0, ( static_cast< void > ( objects->Notify () ), 0 )... };
static_cast< void > ( arr );
// check if all values in rc == true and return true or false
// return result;
}
c++ c++11 variadic-templates
c++ c++11 variadic-templates
edited Nov 21 '18 at 12:52
Swordfish
1
asked Nov 21 '18 at 11:51
RomaRoma
184
edited Nov 21 '18 at 12:52
Swordfish
1
asked Nov 21 '18 at 11:51
RomaRoma
184
edited Nov 21 '18 at 12:52
Swordfish
1
edited Nov 21 '18 at 12:52
Swordfish
1
edited Nov 21 '18 at 12:52
Swordfish
1
1
asked Nov 21 '18 at 11:51
RomaRoma
184
asked Nov 21 '18 at 11:51
RomaRoma
184
asked Nov 21 '18 at 11:51
RomaRoma
184
184
1
Trystd::all_of.
– n.m.
Nov 21 '18 at 12:26
add a comment |
1
Trystd::all_of.
– n.m.
Nov 21 '18 at 12:26
1
1
Try
std::all_of.– n.m.
Nov 21 '18 at 12:26
Try
std::all_of.– n.m.
Nov 21 '18 at 12:26
add a comment |
1 Answer
1
active
oldest
votes
3
struct foo {
bool Notify() const { return /* something */; }
};
template<typename... Objects>
bool callNotifyOnPointerObjects(Objects&&... objects)
{
bool rc{ objects->Notify() ... };
for (auto const &c : rc)
if(!c) return false
return true;
}
Or, instead of the for-loop, use std::all_of() as suggested by @n.m. in a comment:
#include <iterator>
#include <algorithm>
// ...
template<typename... Objects>
bool callNotifyOnPointerObjects(Objects&&... objects)
{
bool rc{ objects->Notify() ... };
return std::all_of(std::begin(rc), std::end(rc), (bool b){ return b; });
}
However, it might be more performant to just
template<typename... Objects>
bool callNotifyOnPointerObjects(Objects&&... objects)
{
return (objects->Notify() + ...) == sizeof...(objects);
}
answered Nov 21 '18 at 12:24
SwordfishSwordfish
1
add a comment |
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1 Answer
1
active
oldest
votes
1 Answer
1
active
oldest
votes
active
oldest
votes
active
oldest
votes
3
struct foo {
bool Notify() const { return /* something */; }
};
template<typename... Objects>
bool callNotifyOnPointerObjects(Objects&&... objects)
{
bool rc{ objects->Notify() ... };
for (auto const &c : rc)
if(!c) return false
return true;
}
Or, instead of the for-loop, use std::all_of() as suggested by @n.m. in a comment:
#include <iterator>
#include <algorithm>
// ...
template<typename... Objects>
bool callNotifyOnPointerObjects(Objects&&... objects)
{
bool rc{ objects->Notify() ... };
return std::all_of(std::begin(rc), std::end(rc), (bool b){ return b; });
}
However, it might be more performant to just
template<typename... Objects>
bool callNotifyOnPointerObjects(Objects&&... objects)
{
return (objects->Notify() + ...) == sizeof...(objects);
}
answered Nov 21 '18 at 12:24
SwordfishSwordfish
1
add a comment |
3
struct foo {
bool Notify() const { return /* something */; }
};
template<typename... Objects>
bool callNotifyOnPointerObjects(Objects&&... objects)
{
bool rc{ objects->Notify() ... };
for (auto const &c : rc)
if(!c) return false
return true;
}
Or, instead of the for-loop, use std::all_of() as suggested by @n.m. in a comment:
#include <iterator>
#include <algorithm>
// ...
template<typename... Objects>
bool callNotifyOnPointerObjects(Objects&&... objects)
{
bool rc{ objects->Notify() ... };
return std::all_of(std::begin(rc), std::end(rc), (bool b){ return b; });
}
However, it might be more performant to just
template<typename... Objects>
bool callNotifyOnPointerObjects(Objects&&... objects)
{
return (objects->Notify() + ...) == sizeof...(objects);
}
answered Nov 21 '18 at 12:24
SwordfishSwordfish
1
add a comment |
3
3
3
struct foo {
bool Notify() const { return /* something */; }
};
template<typename... Objects>
bool callNotifyOnPointerObjects(Objects&&... objects)
{
bool rc{ objects->Notify() ... };
for (auto const &c : rc)
if(!c) return false
return true;
}
Or, instead of the for-loop, use std::all_of() as suggested by @n.m. in a comment:
#include <iterator>
#include <algorithm>
// ...
template<typename... Objects>
bool callNotifyOnPointerObjects(Objects&&... objects)
{
bool rc{ objects->Notify() ... };
return std::all_of(std::begin(rc), std::end(rc), (bool b){ return b; });
}
However, it might be more performant to just
template<typename... Objects>
bool callNotifyOnPointerObjects(Objects&&... objects)
{
return (objects->Notify() + ...) == sizeof...(objects);
}
answered Nov 21 '18 at 12:24
SwordfishSwordfish
1
struct foo {
bool Notify() const { return /* something */; }
};
template<typename... Objects>
bool callNotifyOnPointerObjects(Objects&&... objects)
{
bool rc{ objects->Notify() ... };
for (auto const &c : rc)
if(!c) return false
return true;
}
Or, instead of the for-loop, use std::all_of() as suggested by @n.m. in a comment:
#include <iterator>
#include <algorithm>
// ...
template<typename... Objects>
bool callNotifyOnPointerObjects(Objects&&... objects)
{
bool rc{ objects->Notify() ... };
return std::all_of(std::begin(rc), std::end(rc), (bool b){ return b; });
}
However, it might be more performant to just
template<typename... Objects>
bool callNotifyOnPointerObjects(Objects&&... objects)
{
return (objects->Notify() + ...) == sizeof...(objects);
}
answered Nov 21 '18 at 12:24
SwordfishSwordfish
1
edited Nov 21 '18 at 12:46
answered Nov 21 '18 at 12:24
SwordfishSwordfish
1
answered Nov 21 '18 at 12:24
SwordfishSwordfish
1
answered Nov 21 '18 at 12:24
SwordfishSwordfish
1
1
add a comment |
add a comment |
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Try
std::all_of.– n.m.
Nov 21 '18 at 12:26