Catch2 installation on ubuntu 20.04 #include <catch2/catch.hpp> - c++

Question

I am trying to install Catch2 on ubuntu 20.04.
Used instruction from here.
This is what i do:
$ git clone https://github.com/catchorg/Catch2.git
$ cd Catch2
$ cmake -Bbuild -H. -DBUILD_TESTING=OFF
$ sudo cmake --build build/ --target install
Than it saing me that all ok: link for output.
BUT:
When I try to compile the example: // from here
main.cpp
#define CATCH_CONFIG_MAIN // This tells Catch to provide a main() - only do this in one cpp file
#define CATCH_CONFIG_ENABLE_BENCHMARKING
#include <catch2/catch.hpp>
std::uint64_t Fibonacci(std::uint64_t number) {
return number < 2 ? 1 : Fibonacci(number - 1) + Fibonacci(number - 2);
}
TEST_CASE("Fibonacci") {
CHECK(Fibonacci(0) == 1);
// some more asserts..
CHECK(Fibonacci(5) == 8);
// some more asserts..
// now let's benchmark:
BENCHMARK("Fibonacci 20") {
return Fibonacci(20);
};
BENCHMARK("Fibonacci 25") {
return Fibonacci(25);
};
BENCHMARK("Fibonacci 30") {
return Fibonacci(30);
};
BENCHMARK("Fibonacci 35") {
return Fibonacci(35);
};
}
CMakeLists.txt
cmake_minimum_required(VERSION 3.5 FATAL_ERROR)
project(Persistent-world LANGUAGES CXX)
add_executable(${PROJECT_NAME} main.cpp )
find_package(Catch2 REQUIRED)
target_link_libraries(${PROJECT_NAME} Catch2::Catch2)
It output such ERROR: catch2/catch.hpp: No such file or directory
Thanks in advance

Answer 1

The problem is quite simple: clonning catchorg/Catch2 now gets you a v3 branch by default, which works differently. The most important change is that it is no longer single header, and that the catch2/catch.hpp header no longer exists.
You can either switch to the v2 branch before configuring and installing the build, or adapt your code to the changes in v3, starting with this documentation on v2 -> v3 migration.
To get the default main, link against Catch2::Catch2WithMain target.

Answer 2

Admin helped me.
On catch v3. I need:
cmake_minimum_required(VERSION 3.5)
project(Catch2 LANGUAGES CXX)
add_executable(${PROJECT_NAME} main.cpp )
find_package(Catch2)
target_link_libraries(${PROJECT_NAME} Catch2::Catch2WithMain)
If you just link against Catch2::Catch2, you won't get the default main and have to write your own, and your own main needs to invoke the tests. See e.g. that
Than i understand that with main it should looks like:
#define CATCH_CONFIG_MAIN // This tells Catch to provide a main() - only do this in one cpp file
#define CATCH_CONFIG_ENABLE_BENCHMARKING
#include <catch2/catch_all.hpp>
std::uint64_t Fibonacci(std::uint64_t number) {
return number < 2 ? 1 : Fibonacci(number - 1) + Fibonacci(number - 2);
}
TEST_CASE("Fibonacci") {
CHECK(Fibonacci(0) == 1);
// some more asserts..
CHECK(Fibonacci(5) == 8);
// some more asserts..
// now let's benchmark:
BENCHMARK("Fibonacci 20") {
return Fibonacci(20);
};
BENCHMARK("Fibonacci 25") {
return Fibonacci(25);
};
BENCHMARK("Fibonacci 30") {
return Fibonacci(30);
};
BENCHMARK("Fibonacci 35") {
return Fibonacci(35);
};
}
int main( int argc, char* argv[] )
{
Catch::Session session; // There must be exactly one instance
// writing to session.configData() here sets defaults
// this is the preferred way to set them
int returnCode = session.applyCommandLine( argc, argv );
if( returnCode != 0 ) // Indicates a command line error
return returnCode;
// writing to session.configData() or session.Config() here
// overrides command line args
// only do this if you know you need to
int numFailed = session.run();
// numFailed is clamped to 255 as some unices only use the lower 8 bits.
// This clamping has already been applied, so just return it here
// You can also do any post run clean-up here
return numFailed;
}