1 // 311-Gen-CustomCapture.cpp 2 // Shows how to provide custom capture list to the generator expression 3 4 // Note that using variables inside generators is dangerous and should 5 // be done only if you know what you are doing, because the generators 6 // _WILL_ outlive the variables. Also, even if you know what you are 7 // doing, you should probably use GENERATE_COPY or GENERATE_REF macros 8 // instead. However, if your use case requires having a 9 // per-variable custom capture list, this example shows how to achieve 10 // that. 11 12 #include <catch2/catch.hpp> 13 14 TEST_CASE("Generate random doubles across different ranges", 15 "[generator][example][advanced]") { 16 // Workaround for old libstdc++ 17 using record = std::tuple<double, double>; 18 // Set up 3 ranges to generate numbers from 19 auto r1 = GENERATE(table<double, double>({ 20 record{3, 4}, 21 record{-4, -3}, 22 record{10, 1000} 23 })); 24 25 auto r2(r1); 26 27 // This will take r1 by reference and r2 by value. 28 // Note that there are no advantages for doing so in this example, 29 // it is done only for expository purposes. 30 auto number = Catch::Generators::generate( CATCH_INTERNAL_LINEINFO, __anon6bcbf3f30102null31 [&r1, r2]{ 32 using namespace Catch::Generators; 33 return makeGenerators(take(50, random(std::get<0>(r1), std::get<1>(r2)))); 34 } 35 ); 36 37 REQUIRE(std::abs(number) > 0); 38 } 39 40 // Compiling and running this file will result in 150 successful assertions 41 42