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;

}

edited Nov 21 '18 at 12:52

Swordfish

asked Nov 21 '18 at 11:51

Roma

184

1

Try std::all_of.

– n.m.
Nov 21 '18 at 12:26

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;

}

edited Nov 21 '18 at 12:52

Swordfish

asked Nov 21 '18 at 11:51

Roma

184

1

Try std::all_of.

– n.m.
Nov 21 '18 at 12:26

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;

}

edited Nov 21 '18 at 12:52

Swordfish

asked Nov 21 '18 at 11:51

Roma

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

edited Nov 21 '18 at 12:52

Swordfish

asked Nov 21 '18 at 11:51

Roma

184

edited Nov 21 '18 at 12:52

Swordfish

asked Nov 21 '18 at 11:51

Roma

184

edited Nov 21 '18 at 12:52

Swordfish

edited Nov 21 '18 at 12:52

Swordfish

edited Nov 21 '18 at 12:52

Swordfish

asked Nov 21 '18 at 11:51

Roma

184

asked Nov 21 '18 at 11:51

Roma

184

asked Nov 21 '18 at 11:51

Roma

184

1

Try std::all_of.

– n.m.
Nov 21 '18 at 12:26

add a comment |

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

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);

}

edited Nov 21 '18 at 12:46

answered Nov 21 '18 at 12:24

Swordfish

add a comment |

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1 Answer
1

active

oldest

votes

1 Answer
1

active

oldest

votes

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);

}

edited Nov 21 '18 at 12:46

answered Nov 21 '18 at 12:24

Swordfish

add a comment |

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);

}

edited Nov 21 '18 at 12:46

answered Nov 21 '18 at 12:24

Swordfish

add a comment |

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);

}

edited Nov 21 '18 at 12:46

answered Nov 21 '18 at 12:24

Swordfish

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);

}

edited Nov 21 '18 at 12:46

answered Nov 21 '18 at 12:24

Swordfish

edited Nov 21 '18 at 12:46

answered Nov 21 '18 at 12:24

Swordfish

answered Nov 21 '18 at 12:24

Swordfish

answered Nov 21 '18 at 12:24

Swordfish

add a comment |

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