False positive: [danglingTemporaryLifetime]

[Andreas Grob]

#include <map>

struct A {
    std::map<int, int> m{{1, 1}, {2, 2}, {3, 3}};
};

struct Base {
    virtual auto get() -> A & = 0;
};

struct B : public Base {
    A a{};
    auto get() -> A & override { return a; }
};

int main() {
    B b;
    A &a = b.get();
    auto it = a.m.find(2);
}

cppcheck: commit 62702a6
built with: make MATCHCOMPILER=yes FILESDIR=/usr/share/cppcheck HAVE_RULES=yes

$ cppcheck  main.cpp
Checking main.cpp ...
main.cpp:19:13: error: Using iterator to local container 'm' to temporary. [danglingTemporaryLifetime]                                                                                        
    auto it = a.m.find(2);
            ^
main.cpp:19:16: note: Iterator to container is created here.
    auto it = a.m.find(2);
               ^
main.cpp:4:24: note: Variable created here.
    std::map<int, int> m{{1, 1}, {2, 2}, {3, 3}};
                       ^
main.cpp:19:13: note: Using iterator to local container 'm' to temporary.
    auto it = a.m.find(2);
            ^

The error disappears if you remove the Base struct, it also goes away if you just remove the override keyword. P.ossibly related to False positive: [returnTempReference]

[Daniel Marjamäki]

Thanks! I have created ticket https://trac.cppcheck.net/ticket/9813

[Andreas Grob]

Fixed for me in 48a6852.