Add throwf

cpp.hint

@@ -17,3 +17,6 @@
 
 #define IRIS_FORCEINLINE
 #define IRIS_LIFETIMEBOUND
+
+#define IRIS_THROW_NORETURN [[noreturn]]
+

include/iris/exception.hpp

@@ -0,0 +1,86 @@
+#ifndef IRIS_EXCEPTION_HPP
+#define IRIS_EXCEPTION_HPP
+
+#include <iris/string.hpp>
+
+#include <exception>
+#include <format>
+#include <stdexcept>
+#include <string>
+#include <string_view>
+#include <type_traits>
+#include <utility>
+
+#ifndef IRIS_THROW_IMPL
+# define IRIS_THROW_IMPL(...) throw __VA_ARGS__
+#endif
+
+#ifndef IRIS_THROW_NORETURN
+# define IRIS_THROW_NORETURN [[noreturn]]
+#endif
+
+namespace iris {
+
+namespace detail {
+
+template<class T, class... Args>
+concept constructible_from_string_like_types =
+    std::is_constructible_v<T, Args..., std::string> ||
+    std::is_constructible_v<T, Args..., std::string_view> ||
+    std::is_constructible_v<T, Args..., const char*>;
+
+} // detail
+
+inline namespace error_functions {
+
+template<class E>
+IRIS_THROW_NORETURN void throwf()
+{
+    static_assert(std::is_base_of_v<std::exception, E>);
+    static_assert(std::is_constructible_v<E>);
+    IRIS_THROW_IMPL(E{});
+}
+
+template<class E, class Arg, class... Rest>
+    requires std::is_constructible_v<E, Arg, Rest...>
+IRIS_THROW_NORETURN void throwf(Arg&& arg, Rest&&... rest)
+{
+    static_assert(std::is_base_of_v<std::exception, E>);
+    static_assert(!std::is_base_of_v<std::exception, std::remove_cvref_t<Arg>>, "don't copy/move construct exception types directly");
+    IRIS_THROW_IMPL(E{std::forward<Arg>(arg), std::forward<Rest>(rest)...});
+}
+
+template<class E, class... Args>
+    requires detail::constructible_from_string_like_types<E>
+IRIS_THROW_NORETURN void throwf(std::format_string<Args...> fmt, Args&&... args)
+{
+    static_assert(std::is_base_of_v<std::exception, E>);
+    IRIS_THROW_IMPL(E{std::format(std::move(fmt), std::forward<Args>(args)...)});
+}
+
+template<class E, NotStringLike Arg0, class... Args>
+    requires detail::constructible_from_string_like_types<E, Arg0>
+IRIS_THROW_NORETURN void throwf(Arg0&& arg0, std::format_string<Args...> fmt, Args&&... args)
+{
+    static_assert(std::is_base_of_v<std::exception, E>);
+    IRIS_THROW_IMPL(E{std::forward<Arg0>(arg0), std::format(std::move(fmt), std::forward<Args>(args)...)});
+}
+
+template<class E, NotStringLike Arg0, NotStringLike Arg1, class... Args>
+    requires detail::constructible_from_string_like_types<E, Arg0, Arg1>
+IRIS_THROW_NORETURN void throwf(Arg0&& arg0, Arg1&& arg1, std::format_string<Args...> fmt, Args&&... args)
+{
+    static_assert(std::is_base_of_v<std::exception, E>);
+    IRIS_THROW_IMPL(
+        E{
+            std::forward<Arg0>(arg0), std::forward<Arg1>(arg1),
+            std::format(std::move(fmt), std::forward<Args>(args)...)
+        }
+    );
+}
+
+} // error_functions
+
+} // iris
+
+#endif

include/iris/string.hpp

@@ -13,6 +13,9 @@ concept StringLike = requires(T t) {
     std::basic_string_view{t};
 };
 
+template<class T>
+concept NotStringLike = !StringLike<T>;
+
 } // iris
 
 #endif

test/CMakeLists.txt

@@ -150,7 +150,7 @@ endfunction()
 # Iris tests
 
 if(PROJECT_IS_TOP_LEVEL)
-    if(IRIS_CI_COMPONENT STREQUAL iris)
+    if(NOT DEFINED IRIS_CI_COMPONENT OR IRIS_CI_COMPONENT STREQUAL iris)
         add_subdirectory(rvariant)
 
         set(

test/core.cpp

@@ -6,6 +6,7 @@
 #include <iris/requirements.hpp>
 #include <iris/compare.hpp>
 #include <iris/fixed_string.hpp>
+#include <iris/exception.hpp>
 
 #include <concepts>
 #include <utility>
@@ -452,4 +453,73 @@ TEST_CASE("fixed_string")
     CHECK((std::ranges::equal(str, "foobar"sv)));
 }
 
+
+#define IRIS_TEST_THROWF(expected, E, ...) \
+    CHECK_THROWS_AS( \
+        ([]{ \
+            try { \
+                iris::throwf<E>(__VA_ARGS__); \
+            } catch (std::exception const& e) { \
+                CHECK(e.what() == std::string_view{expected}); \
+                throw; \
+            } \
+        })(), \
+        E \
+    )
+
+TEST_CASE("throwf")
+{
+    class my_exception : public std::runtime_error
+    {
+    public:
+        my_exception(std::string const& name, std::string const& message)
+            : runtime_error(name + ": " + message)
+        {}
+    };
+
+    IRIS_TEST_THROWF("foo", std::runtime_error, "foo");
+    IRIS_TEST_THROWF("foo", std::runtime_error, std::string{"foo"});
+    IRIS_TEST_THROWF("foo", std::runtime_error, std::string{"foo"}.c_str());
+    IRIS_TEST_THROWF("foo", std::runtime_error, std::string_view{"foo"});
+    IRIS_TEST_THROWF("{}", std::runtime_error, "{}");
+    IRIS_TEST_THROWF("42", std::runtime_error, "{}", 42);
+    IRIS_TEST_THROWF("foo", std::runtime_error, "{}", "foo");
+    IRIS_TEST_THROWF("foo", std::runtime_error, "{}", std::string{"foo"});
+    IRIS_TEST_THROWF("foo", std::runtime_error, "{}", std::string{"foo"}.c_str());
+    IRIS_TEST_THROWF("foo", std::runtime_error, "{}", std::string_view{"foo"});
+
+    IRIS_TEST_THROWF("{}: bar", my_exception, "{}", "bar");
+    IRIS_TEST_THROWF("foo: bar", my_exception, "foo", "bar");
+
+    // constructible with argument
+    IRIS_TEST_THROWF("foobar", std::runtime_error, "foobar");
+
+    // constructible with format string
+    IRIS_TEST_THROWF("33 - 4", std::runtime_error, "{} - {}", 33, 4);
+
+    CHECK_THROWS_AS(
+        ([]{
+            try {
+                iris::throwf<std::system_error>(std::make_error_code(std::errc::invalid_argument), "{}", 42);
+            } catch (std::system_error const& e) {
+                CHECK(e.code() == std::make_error_code(std::errc::invalid_argument));
+                throw;
+            }
+        })(),
+        std::system_error
+    );
+
+    CHECK_THROWS_AS(
+        ([]{
+            try {
+                iris::throwf<std::system_error>(33 - 4, std::generic_category(), "{}", 42);
+            } catch (std::system_error const& e) {
+                CHECK((e.code() == std::error_code{33 - 4, std::generic_category()}));
+                throw;
+            }
+        })(),
+        std::system_error
+    );
+}
+
 } // unit_test