如何分辨叮当当格式不要在一行上做短的lambda表达式?

Question

#include <iostream>
int main()
{
auto func = []() { 
std::cout << "hello, world" << std::endl; 
};
func();
}

我想以这种方式保持我的简短 lambda 表达式。但是叮当格式总是让它在一行上。

auto func = []() { std::cout << "hello, world" << std::endl; };

我已经阅读了文档，但找不到正确的设置。这是我的配置：

BasedOnStyle:   LLVM
Language:   Cpp
AccessModifierOffset:   -4
AlignAfterOpenBracket:  Align
AlignConsecutiveAssignments:    true
AlignConsecutiveDeclarations:   true
AlignEscapedNewlines: Left
AlignOperands:  true
AlignTrailingComments:  true
AllowAllParametersOfDeclarationOnNextLine:  true
AllowShortBlocksOnASingleLine:  false
AllowShortCaseLabelsOnASingleLine:  false
AllowShortFunctionsOnASingleLine:   Empty
AllowShortIfStatementsOnASingleLine:    true
AllowShortLoopsOnASingleLine:   false
AlwaysBreakAfterDefinitionReturnType:   None
AlwaysBreakAfterReturnType: None
AlwaysBreakBeforeMultilineStrings:  false
AlwaysBreakTemplateDeclarations:    false
BinPackArguments:   false
BinPackParameters:  false
BraceWrapping:   
AfterClass:   true
AfterControlStatement: true   
AfterEnum: true   
AfterFunction:    true
AfterNamespace:   false
AfterObjCDeclaration: false
AfterStruct:  true
AfterUnion:   false
BeforeCatch:  true
BeforeElse:   true
IndentBraces: false
BreakBeforeBinaryOperators: NonAssignment
BreakBeforeBraces:  Custom
BreakBeforeTernaryOperators:    true
BreakConstructorInitializersBeforeComma:    true
ColumnLimit:    120
CommentPragmas: '^ IWYU pragma:'
ConstructorInitializerAllOnOneLineOrOnePerLine: false
ConstructorInitializerIndentWidth:  4
ContinuationIndentWidth:    4
Cpp11BracedListStyle:   false
DerivePointerAlignment: false
DisableFormat:  false
ExperimentalAutoDetectBinPacking:   false
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
IndentCaseLabels:   true
IndentWidth:    4
IndentWrappedFunctionNames: false
KeepEmptyLinesAtTheStartOfBlocks:   true
MacroBlockBegin:    ''
MacroBlockEnd:  ''
MaxEmptyLinesToKeep:    1
NamespaceIndentation:   Inner
ObjCBlockIndentWidth:   4
ObjCSpaceAfterProperty: false
ObjCSpaceBeforeProtocolList:    true
PenaltyBreakBeforeFirstCallParameter:   19
PenaltyBreakComment:    300
PenaltyBreakFirstLessLess:  120
PenaltyBreakString: 1000
PenaltyExcessCharacter: 1000000
PenaltyReturnTypeOnItsOwnLine:  60
PointerAlignment:   Right
ReflowComments: true
SortIncludes:   true
SortUsingDeclarations: true
SpaceAfterCStyleCast:   false
SpaceAfterTemplateKeyword: true
SpaceBeforeAssignmentOperators: true
SpaceBeforeParens:  ControlStatements
SpaceInEmptyParentheses:    false
SpacesBeforeTrailingComments:   1
SpacesInAngles: false
SpacesInContainerLiterals:  true
SpacesInCStyleCastParentheses:  false
SpacesInParentheses:    false
SpacesInSquareBrackets: false
Standard:   Cpp11
TabWidth:   4
UseTab: Never

我的 clang 格式版本是 7.0.0。如果 lambda 表达式有两行以上，则效果很好。但是当它只有一行时。clang 格式总是在一行中。有时一个短函数，它只体一行，叮当格式也使它在一行中。

Answer 1

从版本 9.0 开始，AllowShortLambdasOnASingleLine选项。请参阅官方文档。

在您的情况下，您需要选项的值为Inline、Empty或None。