bugprone-unused-local-non-trivial-variable¶
Warns when a local non trivial variable is unused within a function. The following types of variables are excluded from this check:
trivial and trivially copyable
references and pointers
exception variables in catch clauses
static or thread local
structured bindings
variables with
[[maybe_unused]]attribute
This check can be configured to warn on all non-trivial variables by setting IncludeTypes to .*, and excluding specific types using ExcludeTypes.
In the this example, my_lock would generate a warning that it is unused.
std::mutex my_lock;
// my_lock local variable is never used
In the next example, future2 would generate a warning that it is unused.
std::future<MyObject> future1;
std::future<MyObject> future2;
// ...
MyObject foo = future1.get();
// future2 is not used.
Options¶
- IncludeTypes¶
Semicolon-separated list of regular expressions matching types of variables to check. By default the following types are checked:
::std::.*mutex
::std::future
::std::basic_string
::std::basic_regex
::std::basic_istringstream
::std::basic_stringstream
::std::bitset
::std::filesystem::path
- ExcludeTypes¶
A semicolon-separated list of regular expressions matching types that are excluded from the IncludeTypes matches. By default it is an empty list.