clang-format: don't break between string and << operator

Question

I have the following line in my C++ code:

std::cout << "done" << "\n";

which clang-format breaks into

std::cout << "done"
          << "\n";

no matter what. I have edited every option that starts with "Break" or "Align":

AlignAfterOpenBracket: DontAlign
AlignArrayOfStructures: None
AlignConsecutiveMacros: 'false'
AlignConsecutiveAssignments: 'false'
AlignConsecutiveBitFields: 'false'
AlignConsecutiveDeclarations: 'false'
AlignEscapedNewlines: DontAlign
AlignOperands:   DontAlign
AlignTrailingComments: 'false'

BreakBeforeBinaryOperators: None
BreakBeforeConceptDeclarations: false
BreakBeforeBraces: Attach
BreakBeforeInheritanceComma: false
BreakInheritanceList: AfterComma
BreakBeforeTernaryOperators: false
BreakConstructorInitializersBeforeComma: false
BreakConstructorInitializers: AfterColon
BreakStringLiterals: false

How can I make it not do this? Version is 14.0.0

Answer 1

clang-format erroneously always puts consecutive << "string" onto separate lines. This is a known bug, first reported in Feb 2020.

Your configuration works for for statements like:

// This doesn't get split over multiple lines;
// it only happens if the column limit is exceeded.
int x = 1 << 2 << 3;

Normally, only if a line is too long:

• BreakBeforeBinaryOperators controls whether the line is broken before/after operators.
• AlignOperands controls horizontal alignment of operators.

However, when a << is followed by a string literal, clang-format will put it onto a separate line, no matter what.