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// RUN: %check_clang_tidy %s cppcoreguidelines-missing-std-forward %t -- -- -fno-delayed-template-parsing
// NOLINTBEGIN
namespace std {
template <typename T> struct remove_reference { using type = T; };
template <typename T> struct remove_reference<T&> { using type = T; };
template <typename T> struct remove_reference<T&&> { using type = T; };
template <typename T> using remove_reference_t = typename remove_reference<T>::type;
template <typename T> constexpr T &&forward(remove_reference_t<T> &t) noexcept;
template <typename T> constexpr T &&forward(remove_reference_t<T> &&t) noexcept;
template <typename T> constexpr remove_reference_t<T> &&move(T &&x);
} // namespace std
// NOLINTEND
struct S {
S();
S(const S&);
S(S&&) noexcept;
S& operator=(const S&);
S& operator=(S&&) noexcept;
};
template <class... Ts>
void consumes_all(Ts&&...);
namespace positive_cases {
template <class T>
void does_not_forward(T&& t) {
// CHECK-MESSAGES: :[[@LINE-1]]:27: warning: forwarding reference parameter 't' is never forwarded inside the function body [cppcoreguidelines-missing-std-forward]
T other = t;
}
template <class T>
void does_not_forward_invoked(T&& t) {
// CHECK-MESSAGES: :[[@LINE-1]]:35: warning: forwarding reference parameter 't' is never forwarded inside the function body [cppcoreguidelines-missing-std-forward]
T other = t();
}
template <class T>
void forwards_pairwise(T&& t) {
// CHECK-MESSAGES: :[[@LINE-1]]:28: warning: forwarding reference parameter 't' is never forwarded inside the function body [cppcoreguidelines-missing-std-forward]
auto first = std::forward<T>(t.first);
auto second = std::forward<T>(t.second);
}
template <class... Ts>
void does_not_forward_pack(Ts&&... ts) {
// CHECK-MESSAGES: :[[@LINE-1]]:36: warning: forwarding reference parameter 'ts' is never forwarded inside the function body [cppcoreguidelines-missing-std-forward]
consumes_all(ts...);
}
template <class T>
class AClass {
template <class U>
AClass(U&& u) : data(u) {}
// CHECK-MESSAGES: :[[@LINE-1]]:14: warning: forwarding reference parameter 'u' is never forwarded inside the function body [cppcoreguidelines-missing-std-forward]
template <class U>
AClass& operator=(U&& u) { }
// CHECK-MESSAGES: :[[@LINE-1]]:25: warning: forwarding reference parameter 'u' is never forwarded inside the function body [cppcoreguidelines-missing-std-forward]
template <class U>
void mixed_params(T&& t, U&& u) {
// CHECK-MESSAGES: :[[@LINE-1]]:32: warning: forwarding reference parameter 'u' is never forwarded inside the function body [cppcoreguidelines-missing-std-forward]
T other1 = std::move(t);
U other2 = std::move(u);
}
T data;
};
template <class T>
void does_not_forward_in_evaluated_code(T&& t) {
// CHECK-MESSAGES: :[[@LINE-1]]:45: warning: forwarding reference parameter 't' is never forwarded inside the function body [cppcoreguidelines-missing-std-forward]
using result_t = decltype(std::forward<T>(t));
unsigned len = sizeof(std::forward<T>(t));
T other = t;
}
template <class T>
void lambda_value_capture(T&& t) {
// CHECK-MESSAGES: :[[@LINE-1]]:31: warning: forwarding reference parameter 't' is never forwarded inside the function body [cppcoreguidelines-missing-std-forward]
[=]() { T other = std::forward<T>(t); };
}
template <class T>
void lambda_value_capture_copy(T&& t) {
// CHECK-MESSAGES: :[[@LINE-1]]:36: warning: forwarding reference parameter 't' is never forwarded inside the function body [cppcoreguidelines-missing-std-forward]
[&,t]() { T other = std::forward<T>(t); };
}
template <typename X>
void use(const X &x) {}
template <typename X, typename Y>
void foo(X &&x, Y &&y) {
// CHECK-MESSAGES: :[[@LINE-1]]:21: warning: forwarding reference parameter 'y' is never forwarded inside the function body [cppcoreguidelines-missing-std-forward]
use(std::forward<X>(x));
use(y);
}
} // namespace positive_cases
namespace negative_cases {
template <class T>
void just_a_decl(T&&t);
template <class T>
void does_forward(T&& t) {
T other = std::forward<T>(t);
}
template <class... Ts>
void does_forward_pack(Ts&&... ts) {
consumes_all(std::forward<Ts>(ts)...);
}
void pass_by_value(S s) {
S other = std::move(s);
}
void lvalue_ref(S& s) {
S other = std::move(s);
}
void rvalue_ref(S&& s) {
S other = std::move(s);
}
template <class T>
void templated_rvalue_ref(std::remove_reference_t<T>&& t) {
T other = std::move(t);
}
template <class T>
class AClass {
template <class U>
AClass(U&& u) : data(std::forward<U>(u)) {}
template <class U>
AClass& operator=(U&& u) {
data = std::forward<U>(u);
}
void rvalue_ref(T&& t) {
T other = std::move(t);
}
T data;
};
template <class T>
void lambda_value_reference(T&& t) {
[&]() { T other = std::forward<T>(t); };
}
template<typename T>
void lambda_value_reference_capture_list_ref_1(T&& t) {
[=, &t] { T other = std::forward<T>(t); };
}
template<typename T>
void lambda_value_reference_capture_list_ref_2(T&& t) {
[&t] { T other = std::forward<T>(t); };
}
template<typename T>
void lambda_value_reference_capture_list(T&& t) {
[t = std::forward<T>(t)] { t(); };
}
template <class T>
void lambda_value_reference_auxiliary_var(T&& t) {
[&x = t]() { T other = std::forward<T>(x); };
}
} // namespace negative_cases
namespace deleted_functions {
template <typename T>
void f(T &&) = delete;
struct S {
template <typename T>
S(T &&) = delete;
template <typename T>
void operator&(T &&) = delete;
};
} // namespace deleted_functions
namespace unused_arguments {
template<typename F>
void unused_argument1(F&&) {}
template<typename F>
void unused_argument2([[maybe_unused]] F&& f) {}
template<typename F>
void unused_argument3(F&& _) {}
} // namespace unused_arguments
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