[clang-format] change constructor init list to colon on newline, break after comma for longer lines

2 files changed, 32 insertions, 2 deletions

diff --git a/.clang-format b/.clang-format
index c0ec891d43..02f730e6d6 100644
--- a/.clang-format
+++ b/.clang-format
@@ -22,12 +22,13 @@ BinPackParameters: false
 BreakBeforeBinaryOperators: None
 BreakBeforeBraces: Allman
 BreakBeforeTernaryOperators: true
-BreakConstructorInitializersBeforeComma: true
+BreakConstructorInitializersBeforeComma: false
+BreakConstructorInitializers: BeforeColon
 BreakAfterJavaFieldAnnotations: false
 BreakStringLiterals: true
 ColumnLimit:     100
 CommentPragmas:  '^ IWYU pragma:'
-ConstructorInitializerAllOnOneLineOrOnePerLine: false
+ConstructorInitializerAllOnOneLineOrOnePerLine: true
 ConstructorInitializerIndentWidth: 2
 ContinuationIndentWidth: 4
 Cpp11BracedListStyle: true
diff --git a/docs/CODE_GUIDELINES.md b/docs/CODE_GUIDELINES.md
index 63f1a5195a..07c12991fe 100644
--- a/docs/CODE_GUIDELINES.md
+++ b/docs/CODE_GUIDELINES.md
@@ -44,6 +44,7 @@
   * [11.3. Overriding virtual functions](#113-overriding-virtual-functions)
   * [11.4. Default member initialization](#114-default-member-initialization)
   * [11.5. Destructors in interfaces](#115-destructors-in-interfaces)
+  * [11.6. Constructor Initialzation Lists](#116-constructor-initialzation-lists)
 * [12. Other conventions](#12-other-conventions)
   * [12.1. Output parameters](#121-output-parameters)
   * [12.2. Casts](#122-casts)
@@ -73,6 +74,9 @@ We currently target the C++11 language standard. Do use C++11 features when poss
 
 ## 3. Formatting
 
+### Line length
+The `ColumnLimit` in `.clang-format` is set to `100` which defines line length (in general where lines should be broken) that allows two editors side by side on a 1080p screen for diffs.
+
 ### 3.1. Braces
 Curly braces always go on a new line.
 
@@ -632,6 +636,31 @@ class Foo
 
 A class with any virtual functions should have a destructor that is either public and virtual or else protected and nonvirtual (cf. [ISO C++ guidelines](http://isocpp.github.io/CppCoreGuidelines/CppCoreGuidelines#Rc-dtor-virtual)).
 
+### 11.6. Constructor Initialzation Lists
+
+For lines up to [line length](#line-length) everything stays on one line, excluding the braces which must be on the following lines.
+
+```cpp
+MyClass::CMyClass(bool bBoolArg, int iIntegerArg) : m_bArg(bBoolArg), m_iArg(iIntegerArg)
+{
+}
+```
+
+For longer lines, break before colon and after comma.
+
+```cpp
+MyClass::CMyClass(bool bBoolArg,
+                  int iIntegerArg,
+                  const std::string& strSomeText,
+                  const std::shared_ptr<CMyOtherClass>& myOtherClass)
+  : m_bBoolArg(bBoolArg),
+    m_iIntegerArg(iIntegerArg),
+    m_strSomeText(strSomeText),
+    m_myOtherClass(myOtherClass)
+{
+}
+```
+
 ## 12. Other conventions
 
 ### 12.1. Output parameters