catch2/include/internal/catch_matchers_generic.cpp

#include "catch_matchers_generic.hpp"

std::string Catch::Matchers::Generic::Detail::finalizeDescription(const std::string& desc) {
    if (desc.empty()) {
        return "matches undescribed predicate";
    } else {
        return "matches predicate: \"" + desc + '"';
    }
}
Add PredicateMatcher that takes an arbitrary predicate functions Also adds `Predicate` helper function to create `PredicateMatcher`. Because of limitations in type inference it needs to be explicitly typed, like so `Predicate<std::string>([](std::string const& str) { ... })`. It also takes an optional second argument for description of the predicate. It is possible to infer the argument with sufficient TMP, see https://stackoverflow.com/questions/43560492/how-to-extract-lambdas-return-type-and-variadic-parameters-pack-back-from-gener/43561563#43561563 but I don't think that the magic is worth introducing ATM. Closes #1236 2018-04-03 23:28:14 +02:00			`#include "catch_matchers_generic.hpp"`

			`std::string Catch::Matchers::Generic::Detail::finalizeDescription(const std::string& desc) {`
			`if (desc.empty()) {`
			`return "matches undescribed predicate";`
			`} else {`
			`return "matches predicate: \"" + desc + '"';`
			`}`
			`}`