Thanks for using Compiler Explorer
Sponsors
Jakt
C++
Ada
Analysis
Android Java
Android Kotlin
Assembly
C
C3
Carbon
C++ (Circle)
CIRCT
Clean
CMake
CMakeScript
COBOL
C++ for OpenCL
MLIR
Cppx
Cppx-Blue
Cppx-Gold
Cpp2-cppfront
Crystal
C#
CUDA C++
D
Dart
Elixir
Erlang
Fortran
F#
Go
Haskell
HLSL
Hook
Hylo
ispc
Java
Julia
Kotlin
LLVM IR
LLVM MIR
Modula-2
Nim
Objective-C
Objective-C++
OCaml
OpenCL C
Pascal
Pony
Python
Racket
Ruby
Rust
Snowball
Scala
Solidity
Spice
Swift
LLVM TableGen
Toit
TypeScript Native
V
Vala
Visual Basic
Zig
Javascript
GIMPLE
cppx source #1
Output
Compile to binary object
Link to binary
Execute the code
Intel asm syntax
Demangle identifiers
Verbose demangling
Filters
Unused labels
Library functions
Directives
Comments
Horizontal whitespace
Debug intrinsics
Compiler
CppCon 2017
CppCon 2018
p1240r1
p1240r2 trunk
p2320 trunk
Options
Source code
#include <iostream> #include <experimental/meta> #include <experimental/compiler> using namespace std::experimental; namespace traits { template<typename T> consteval bool is_interface_impl() { constexpr meta::info refl = ^T; if constexpr (meta::is_class(refl)) { template for (constexpr meta::info e : meta::members_of(refl)) { // interfaces SHALL NOT have data members if constexpr (meta::is_data_member(e)) { return false; } // every user function in interfaces SHOULD BE public and pure virtual if constexpr (meta::is_function(e) && !meta::is_special_member_function(e)) { if constexpr (!meta::is_public(e) || !meta::is_pure_virtual(e)) { return false; } } // the destructor SHOULD BE virtual and defaulted if constexpr (meta::is_function(e) && meta::is_destructor(e)) { if constexpr (!meta::is_public(e) || !meta::is_defaulted(e) || !meta::is_virtual(e)) { return false; } } } return true; } return false; } template<typename T> constexpr bool is_interface = is_interface_impl<T>(); } // namespace traits // IS NOT abstract, IS NOT interface class foo { public: void foo_void(); private: int _foo_int; }; static_assert(not std::is_abstract_v<foo>); static_assert(not traits::is_interface<foo>); // IS abstract, IS NOT interface class bar { public: virtual void bar_void() = 0; std::string bar_string(); private: int _foo_int; }; static_assert( std::is_abstract_v<bar>); static_assert(not traits::is_interface<foo>); // IS abstract, IS NOT interface class fizz { public: virtual void fizz_void() = 0; std::string fizz_string(); }; static_assert( std::is_abstract_v<fizz>); static_assert(not traits::is_interface<fizz>); // IS abstract, IS NOT interface class buzz { public: virtual void buzz_void() = 0; virtual std::string buzz_string() = 0; }; static_assert( std::is_abstract_v<buzz>); static_assert(not traits::is_interface<buzz>); // IS abstract, IS NOT interface class biba { public: virtual ~biba() { /* ... not defaulted dtor ... */ }; virtual void biba_void() = 0; virtual std::string biba_string() = 0; }; static_assert( std::is_abstract_v<biba>); static_assert(not traits::is_interface<biba>); // IS abstract, IS interface class boba { public: virtual ~boba() = default; virtual void boba_void() = 0; virtual std::string boba_string() = 0; }; static_assert( std::is_abstract_v<boba>); static_assert( traits::is_interface<boba>); int main() { std::cout << "compiled!" << std::endl; }
Become a Patron
Sponsor on GitHub
Donate via PayPal
Source on GitHub
Mailing list
Installed libraries
Wiki
Report an issue
How it works
Contact the author
CE on Mastodon
About the author
Statistics
Changelog
Version tree