Support Clang format 15 (#155)

* Support Clang Format 15

This version mostly add support for the C++20 `requires` clause.

* Fix C++ standard used in Clang Format config

Author: tristan0x

.bbp-project.yaml

@@ -1,7 +1,7 @@
 tools:
   ClangFormat:
     enable: True
-    version: ~=14.0
+    version: ~=15.0
   CMakeFormat:
     enable: True
   Flake8:

cpp/clang-format-13

@@ -96,7 +96,7 @@ SpacesInContainerLiterals: false
 SpacesInCStyleCastParentheses: false
 SpacesInParentheses: false # '(' style
 SpacesInSquareBrackets: false
-Standard: c++14
+Standard: c++17
 TabWidth: 4
 UseTab: Never
 ...

cpp/clang-format-14

@@ -100,7 +100,7 @@ SpacesInContainerLiterals: false
 SpacesInCStyleCastParentheses: false
 SpacesInParentheses: false # '(' style
 SpacesInSquareBrackets: false
-Standard: c++14
+Standard: c++17
 TabWidth: 4
 UseTab: Never
 ...

cpp/clang-format-15

@@ -0,0 +1,108 @@
+---
+AccessModifierOffset: -2
+AlignAfterOpenBracket: Align
+AlignArrayOfStructures: None
+AlignConsecutiveAssignments: false
+AlignConsecutiveDeclarations: false
+AlignConsecutiveMacros: true
+AlignEscapedNewlinesLeft: true
+AlignOperands: true
+AlignTrailingComments: true
+AllowAllParametersOfDeclarationOnNextLine: false
+AllowShortBlocksOnASingleLine: false
+AllowShortCaseLabelsOnASingleLine: false
+AllowShortFunctionsOnASingleLine: Empty
+AllowShortIfStatementsOnASingleLine: false
+AllowShortLoopsOnASingleLine: false
+AlwaysBreakBeforeMultilineStrings: true
+AlwaysBreakTemplateDeclarations: true
+BasedOnStyle: WebKit
+BinPackArguments: false
+BinPackParameters: false
+BraceWrapping:
+  AfterClass: false
+  AfterControlStatement: false
+  AfterEnum: false
+  AfterExternBlock: false
+  AfterFunction: false
+  AfterNamespace: false
+  AfterStruct: false
+  AfterUnion: false
+  BeforeCatch: false
+  BeforeElse: false
+BreakBeforeBraces: Custom
+BreakBeforeBinaryOperators: false
+BreakBeforeConceptDeclarations: true
+BreakBeforeTernaryOperators: true
+BreakConstructorInitializersBeforeComma: true
+BreakStringLiterals: true
+ColumnLimit: 100
+CommentPragmas:  '^ IWYU pragma:'
+ConstructorInitializerAllOnOneLineOrOnePerLine: false
+ConstructorInitializerIndentWidth: 4
+ContinuationIndentWidth: 4
+Cpp11BracedListStyle: true
+DerivePointerAlignment: false
+DerivePointerBinding: true
+EmptyLineBeforeAccessModifier: Leave
+EmptyLineAfterAccessModifier: Leave
+ExperimentalAutoDetectBinPacking: false
+FixNamespaceComments: true
+ForEachMacros:   [ foreach, Q_FOREACH, BOOST_FOREACH ]
+IncludeCategories:
+  - Regex:           '^"(llvm|llvm-c|clang|clang-c)/'
+    Priority:        2
+  - Regex:           '^(<|"(gtest|isl|json)/)'
+    Priority:        3
+  - Regex:           '.*'
+    Priority:        1
+IncludeIsMainRegex: '$'
+IndentAccessModifiers: false
+IndentCaseLabels: false
+IndentPPDirectives: None
+IndentRequiresClause: false
+IndentWidth:     4
+IndentWrappedFunctionNames: false
+InsertBraces: False
+KeepEmptyLinesAtTheStartOfBlocks: false
+LambdaBodyIndentation: Signature
+Language: Cpp
+MaxEmptyLinesToKeep: 2
+NamespaceIndentation: None
+PenaltyBreakAssignment: 40
+PenaltyBreakBeforeFirstCallParameter: 100
+PenaltyBreakComment: 60
+PenaltyBreakFirstLessLess: 120
+PenaltyBreakString: 1000
+PenaltyExcessCharacter: 1000000
+PenaltyReturnTypeOnItsOwnLine: 200
+PointerAlignment: Left
+PointerBindsToType: true
+PPIndentWidth: -1
+PackConstructorInitializers: Never
+QualifierAlignment: Left
+ReflowComments:  true
+RemoveBracesLLVM: false
+RequiresClausePosition: OwnLine
+SeparateDefinitionBlocks: Always
+SortIncludes: true
+SpaceAfterCStyleCast: true
+SpaceAfterTemplateKeyword: true
+SpaceBeforeAssignmentOperators: true
+SpaceBeforeCpp11BracedList: false
+SpaceBeforeCtorInitializerColon: false
+SpaceBeforeInheritanceColon: false
+SpaceBeforeParens: ControlStatements
+SpaceBeforeRangeBasedForLoopColon: false
+SpaceInEmptyBlock: false
+SpaceInEmptyParentheses: false
+SpacesBeforeTrailingComments: 2
+SpacesInAngles: false # '< ' style
+SpacesInContainerLiterals: false
+SpacesInCStyleCastParentheses: false
+SpacesInParentheses: false # '(' style
+SpacesInSquareBrackets: false
+Standard: c++20
+TabWidth: 4
+UseTab: Never
+...

cpp/formatting/README.md

@@ -367,8 +367,8 @@ bool value =
 ```cpp
 template <typename T>
 concept Hashable = requires(T a) {
-    { std::hash<T>{}(a) } -> std::convertible_to<std::size_t>;
-};
+                       { std::hash<T>{}(a) } -> std::convertible_to<std::size_t>;
+                   };
 
 ```
 ### Clang-Format configuration
@@ -455,8 +455,6 @@ void sort(It begin, It end) {
 
 
 ```
-### Clang-Format configuration
-* `IndentRequires: False`
 
 ## Use 4 columns for indentation
 
@@ -537,6 +535,36 @@ const int* a;
 ### Clang-Format configuration
 * `QualifierAlignment: Left`
 
+## The C++20 `requires` clause is put in its own line
+
+### Example
+```cpp
+template <typename T>
+concept Addable = requires(T t) { ++t; };
+
+template <typename T>
+requires Addable<T>
+struct Foo {
+    // ...
+};
+
+template <typename T>
+requires Addable<T>
+void bar(T t){
+    // ...
+};
+
+template <typename T>
+void baz(T t)
+requires Addable<T>
+{
+    //...
+};
+
+```
+### Clang-Format configuration
+* `RequiresClausePosition: OwnLine`
+
 ## Specifies the use of empty lines to separate definition blocks, including classes, structs,
 enums, and functions.
 

cpp/formatting/formatting.py

@@ -46,7 +46,7 @@ def get_cf_data(line):
         with open(file) as istr:
             content = [line.rstrip() for line in istr.readlines()]
         # retrieve title
-        assert is_comment(content[0])
+        assert is_comment(content[0]), f"{file}: first line may be '// TITLE'"
         attrs["title"] = content[0].lstrip("//").lstrip()
         i = 1
         # eat empty lines

cpp/formatting/snippets/BreakBeforeConceptDeclarations.cpp

@@ -2,5 +2,5 @@
 
 template <typename T>
 concept Hashable = requires(T a) {
-    { std::hash<T>{}(a) } -> std::convertible_to<std::size_t>;
-};
+                       { std::hash<T>{}(a) } -> std::convertible_to<std::size_t>;
+                   };

cpp/formatting/snippets/IndentRequires.cpp

@@ -2,7 +2,7 @@
 
 template <typename It>
 requires Iterator<It>
-    // clang-format off
+// clang-format off
 void sort(It begin, It end) {
     //....
 }

cpp/formatting/snippets/RequiresClausePosition.cpp

@@ -0,0 +1,23 @@
+// The C++20 `requires` clause is put in its own line
+
+template <typename T>
+concept Addable = requires(T t) { ++t; };
+
+template <typename T>
+requires Addable<T>
+struct Foo {
+    // ...
+};
+
+template <typename T>
+requires Addable<T>
+void bar(T t){
+    // ...
+};
+
+template <typename T>
+void baz(T t)
+requires Addable<T>
+{
+    //...
+};