CPP Quiz

A quiz about C++ quirkiness and subtle syntatic constructs to raise awareness for the things that can go wrong.

1. Updates
C++Quiz
Felix Morgner
Computer Science
Hochschule f¨ur Technik Rapperswil
February 24, 2016

2. Updates

3. Updates

4. Updates
What we will see
Quirky stuff
Undened Behavior
Unspecied things

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Scoring
+1 per correct answer
+1 per correct reason
-1 per wrong answers

6. Updates
#include
struct
int
int
};
int
S o{};
std::cout << o.memfun();
std::cout << S{}.memfun();
}

7. Updates
#include
struct
virtual;
float
float
};
struct
float
};
int
//:(float)
//:(void *)
std::cout <<(B) <<\n';
std::cout <<(D) <<\n';
}

8. Updates
#include
struct
int
std::cout <<(S) <<\n';
}

9. Updates
#include
autounsigned
(***(int* * *)n)++;
}
int
int
auto
auto
autounsigned) &p2;
f(p3);
std::cout << (**(int* * *)p3 == &n) <<;
std::cout <<*p1 <<\n';
}

10. Updates
#include
int
char'c'};
char*ptr1;
char * *ptr2{&ptr1};
*ptr2 = &c;
(*ptr1)++;
std::cout << c <<\n';
}

11. Updates
#include
int
{
https://github.com/fmorgner/cppquiz
std::cout <<cppugzh\n";
}

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#include
struct
S() { std::cout <<c"; }
~S() { std::cout <<d"; }
};
int
int
mark:
S s{};
while(!i++) {
goto
}
}

13. Updates
#include
#include
#include
using
int
int
[=]{
cout << std::is_same<decltype( j ),
<< std::is_same<decltype((j)),
<< std::is_same<int
}();
}

14. Updates
#include
struct
A() =;
A(AA\n"; }
};
struct
B() =;
B(BB\n"; }
};
auto
int
A a{};
B b{};
[=]{
std::cout <<(a) <<\n';
f(b);
}();
}

15. Updates
#include
struct
template<typename
E(Types
};
template<typename
auto
E{(std::cout << args)..., std::cout <<\n'};
}
int
using
println("C",+',+"s,RocksMySocks");
}

16. Updates
#include
template<typename
auto
template<typename
auto
call((std::cout << args)..., std::cout <<\n');
}
int
using
println("C",+',+"s,RocksMySocks");
}

17. Updates
#include
#include
#include
int
autocppug";
std::vector<std::string> v{a, a, a};
for(auto
std::cout << s;
}
std::cout <<\n'\n';
}

18. Updates
#include
#include
#include
int
autocppug";
std::vector<std::string> v{{a, a, a}};
for(auto
std::cout << s;
}
std::cout <<\n'\n';
}

19. Updates
#include
#include
#include
int
autocppug";
std::vector<std::string> v{{a, a}};
for(auto
std::cout << s;
}
std::cout <<\n'\n';
}

20. Updates
#include
voidlong) {
std::cout << 1 <<\n';
}
voidfloat) {
std::cout << 2 <<\n';
}
int
f(4);
}

21. Updates
#include
voidint,,,);
voidint,,,
voidint,,);
voidint,,);
voidint,,);
voidint
std::cout << a << b << c << d <<\n';
}
int
f();
}

22. Updates
#include
template<typename
void
std::cout << 1;
}
template<typename
void
o(a);
}
voidfloat) {
std::cout << 2;
}
int
f(1.0f);
}

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#include
int
auto
x = 42;
std::cout << x;
}

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int

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int
<:=??)??<
??(&:><%
??(]<%??>();
%>();
}();
%>

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int
[=]{
[&]{
[]{}();
}();
}();
}

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Thanks
https://www.youtube.com/watch?v=rNNnPrMHsAA - Piotr
Padlewski - C++ WAT
http://cppquiz.org/- C++ Quiz
http://olvemaudal.com/ - Olve Maudal
ISO14882:2014

28. Updates
Code and Slides
https://github.com/fmorgner/cpp-quiz
http://www.slideshare.net/fmorgner/cpp-quiz