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fallthrough

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Whenever a case is ended in a switch, the code of the next case will get executed. This last one can be prevented by using the ´break` statement. As this so-called fallthrough behavior can introduce bugs when not intended, several compilers and static analyzers give a warning on this.

From C++17 on, a standard attribute was introduced to indicate that the warning is not needed when the code is meant to fall through. Compilers can safely give warnings when a case is ended without break or [[fallthrough]] and has at least one statement. 

switch(input) {
    case 2011:
    case 2014:
    case 2017:
        std::cout << "Using modern C++" << std::endl;
        [[fallthrough]]; // > No warning
    case 1998:
    case 2003:
        standard = input;
}

See the proposal for more detailed examples on how [[fallthrough]] can be used.

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Attributes:
* Attributes
* fallthrough
* deprecated and deprecatedreason
* nodiscard
* noreturn
* maybe unused
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0 Getting started
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3 Operator precedence
4 Floating point arithmetic
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102 Attributes
103 Internationalization
104 Profiling
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110 C++ vs. C++ 11 vs C++ 17
111 Inline functions
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142 decltype
143 Digit separators
144 C++ Containers
145 Arithmetic meta-programming
146 Contributors