Added test case for C++20 concepts with variadic params

CHANGELOG.md

@@ -1,5 +1,6 @@
 # CHANGELOG
 
+  * Added initial support for C++20 concept rendering (#96)
   * Added support for plain C11 translation units (#97)
   * Added 'row' and 'column' layout hints for aligning elements (#90)
   * Added 'together' layout hint for grouping elements (#43)

README.md

@@ -29,6 +29,7 @@ Main features supported so far include:
     * Optional package generation from namespaces
     * Interactive links to online code to classes, methods and class fields in SVG diagrams
     * Support for plain C99/C11 code (struct and units relationships)
+    * C++20 concept constraints
 * **Sequence diagram generation**
     * Generation of sequence diagram from specific method or function
     * Generation of loop and conditional statements

tests/CMakeLists.txt

@@ -3,7 +3,7 @@ file(GLOB_RECURSE TEST_CASE_SOURCES t*/*.cc t*/*.c t*/src/*.c)
 file(GLOB_RECURSE TEST_CASE_CONFIGS t*/.clang-uml)
 file(GLOB_RECURSE TEST_CONFIG_YMLS test_config_data/*.yml)
 
-set(TEST_CASES_REQUIRING_CXX20 t00056)
+set(TEST_CASES_REQUIRING_CXX20 t00056 t00058)
 
 set(CLANG_UML_TEST_LIBRARIES
         clang-umllib

tests/t00058/.clang-uml

@@ -0,0 +1,15 @@
+compilation_database_dir: ..
+output_directory: puml
+diagrams:
+  t00058_class:
+    type: class
+    glob:
+      - ../../tests/t00058/t00058.cc
+    include:
+      namespaces:
+        - clanguml::t00058
+    using_namespace:
+      - clanguml::t00058
+    plantuml:
+      after:
+        - '{{ alias("same_as_first_type<T,Args...>") }} ..> {{ alias("first_type<T,Args...>") }}'

tests/t00058/t00058.cc

@@ -0,0 +1,44 @@
+#include <string>
+#include <type_traits>
+#include <vector>
+
+// Based on a blog post:
+// https://andreasfertig.blog/2020/08/cpp20-concepts-testing-constrained-functions/
+
+namespace clanguml {
+namespace t00058 {
+
+template <typename T, typename... Args> struct first_type {
+    using type = T;
+};
+
+template <typename... Args>
+using first_type_t = typename first_type<Args...>::type;
+
+// TODO: Dependency of this concept on first_type<> template does not currently
+//       work due to the fact that I don't know how to extract that information
+//       from clang::DependentNameType to which first_type_t<> resolves to...
+template <typename T, typename... Args>
+concept same_as_first_type = std::is_same_v<std::remove_cvref_t<T>,
+    std::remove_cvref_t<first_type_t<Args...>>>;
+
+template <typename T, typename... Args>
+    requires same_as_first_type<T, Args...>
+struct A {
+    std::vector<T> a;
+};
+
+template <typename T, typename P, typename... Args>
+    requires same_as_first_type<T, Args...>
+struct B {
+    std::vector<T> b;
+    P bb;
+};
+
+struct R {
+    A<int, int, double, std::string> aa;
+    B<int, std::string, int, double, A<int, int>> bb;
+};
+
+}
+}

tests/t00058/test_case.h

@@ -0,0 +1,69 @@
+/**
+ * tests/t00058/test_case.h
+ *
+ * Copyright (c) 2021-2023 Bartek Kryza <bkryza@gmail.com>
+ *
+ * Licensed under the Apache License, Version 2.0 (the "License");
+ * you may not use this file except in compliance with the License.
+ * You may obtain a copy of the License at
+ *
+ *     http://www.apache.org/licenses/LICENSE-2.0
+ *
+ * Unless required by applicable law or agreed to in writing, software
+ * distributed under the License is distributed on an "AS IS" BASIS,
+ * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+ * See the License for the specific language governing permissions and
+ * limitations under the License.
+ */
+
+TEST_CASE("t00058", "[test-case][class]")
+{
+    auto [config, db] = load_config("t00058");
+
+    auto diagram = config.diagrams["t00058_class"];
+
+    REQUIRE(diagram->name == "t00058_class");
+
+    auto model = generate_class_diagram(*db, diagram);
+
+    REQUIRE(model->name() == "t00058_class");
+
+    auto puml = generate_class_puml(diagram, *model);
+    AliasMatcher _A(puml);
+
+    REQUIRE_THAT(puml, StartsWith("@startuml"));
+    REQUIRE_THAT(puml, EndsWith("@enduml\n"));
+
+    REQUIRE_THAT(puml, IsClassTemplate("A", "int,int,double,std::string"));
+    REQUIRE_THAT(
+        puml, IsClassTemplate("B", "int,std::string,int,double,A<int,int>"));
+
+    REQUIRE_THAT(puml, IsConcept(_A("same_as_first_type<T,Args...>")));
+
+    REQUIRE_THAT(puml,
+        IsConstraint(_A("A<T,Args...>"), _A("same_as_first_type<T,Args...>"),
+            "T,Args..."));
+
+    REQUIRE_THAT(puml,
+        IsConstraint(_A("B<T,P,Args...>"), _A("same_as_first_type<T,Args...>"),
+            "T,Args..."));
+
+    REQUIRE_THAT(puml,
+        IsAggregation(_A("R"), _A("A<int,int,double,std::string>"), "+aa"));
+    REQUIRE_THAT(puml,
+        IsAggregation(
+            _A("R"), _A("B<int,std::string,int,double,A<int,int>>"), "+bb"));
+
+    REQUIRE_THAT(puml,
+        IsInstantiation(
+            _A("A<T,Args...>"), _A("A<int,int,double,std::string>")));
+    REQUIRE_THAT(puml,
+        IsInstantiation(_A("B<T,P,Args...>"),
+            _A("B<int,std::string,int,double,A<int,int>>")));
+
+    REQUIRE_THAT(puml,
+        IsDependency(
+            _A("same_as_first_type<T,Args...>"), _A("first_type<T,Args...>")));
+
+    save_puml(config.output_directory() + "/" + diagram->name + ".puml", puml);
+}

tests/test_cases.cc

@@ -259,7 +259,9 @@ using namespace clanguml::test::matchers;
 #include "t00056/test_case.h"
 #endif
 #include "t00057/test_case.h"
-
+#if defined(ENABLE_CXX_STD_20_TEST_CASES)
+#include "t00058/test_case.h"
+#endif
 ///
 /// Sequence diagram tests
 ///

tests/test_cases.yaml

@@ -163,11 +163,14 @@ test_cases:
       title: Test case for `row` and `column` layout hints
       description:
     - name: t00056
-      title: Basic C++ concepts test case
+      title: Basic C++20 concepts test case
       description:
     - name: t00057
       title: Test case C99/C11 translation units with structs and unions
       description:
+    - name: t00058
+      title: Test case for concepts with variadic parameters and type aliases
+      description:
   Sequence diagrams:
     - name: t20001
       title: Basic sequence diagram test case

util/generate_test_case.py

@@ -31,6 +31,12 @@ CLASS_DIAGRAM_TEST_CASE_EXAMPLES = """
     // Check if class templates exist
     //REQUIRE_THAT(puml, IsClassTemplate("A", "T,P,CMP,int N"));
     
+    // Check concepts
+    //REQUIRE_THAT(puml, IsConcept(_A("AConcept<T>")));
+    //REQUIRE_THAT(puml,
+    //    IsConceptRequirement(
+    //        _A("AConcept<T,P>"), "sizeof (T) > sizeof (P)"));
+
     // Check if all enums exist
     //REQUIRE_THAT(puml, IsEnum(_A("Lights")));
     
@@ -49,8 +55,8 @@ CLASS_DIAGRAM_TEST_CASE_EXAMPLES = """
     // Check if all relationships exist
     //REQUIRE_THAT(puml, IsAssociation(_A("D"), _A("A"), "-as"));
     //REQUIRE_THAT(puml, IsDependency(_A("R"), _A("B")));
-    //REQUIRE_THAT(puml, IsAggregation(_A("R"), _A("D")));
-    //REQUIRE_THAT(puml, IsComposition(_A("R"), _A("D")));
+    //REQUIRE_THAT(puml, IsAggregation(_A("R"), _A("D"), "-ag"));
+    //REQUIRE_THAT(puml, IsComposition(_A("R"), _A("D"), "-ac"));
     //REQUIRE_THAT(puml, IsInstantiation(_A("ABCD::F<T>"), _A("F<int>")));
 """