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// RUN: %clang_cc1 -std=c++0x -Wno-unused-value -fsyntax-only -verify -fblocks %s
namespace std { class type_info; };
namespace ExplicitCapture {
class C {
int Member;
static void Overload(int);
void Overload();
virtual C& Overload(float);
void ImplicitThisCapture() {
[](){(void)Member;}; // expected-error {{'this' cannot be implicitly captured in this context}}
[&](){(void)Member;};
[this](){(void)Member;};
[this]{[this]{};};
[]{[this]{};};// expected-error {{'this' cannot be implicitly captured in this context}}
[]{Overload(3);};
[]{Overload();}; // expected-error {{'this' cannot be implicitly captured in this context}}
[]{(void)typeid(Overload());};
[]{(void)typeid(Overload(.5f));};// expected-error {{'this' cannot be implicitly captured in this context}}
}
};
void f() {
[this] () {}; // expected-error {{'this' cannot be captured in this context}}
}
}
namespace ReturnDeduction {
void test() {
[](){ return 1; };
[](){ return 1; };
[](){ return ({return 1; 1;}); };
[](){ return ({return 'c'; 1;}); }; // expected-error {{must match previous return type}}
[]()->int{ return 'c'; return 1; };
[](){ return 'c'; return 1; }; // expected-error {{must match previous return type}}
[]() { return; return (void)0; };
[](){ return 1; return 1; };
}
}
namespace ImplicitCapture {
void test() {
int a = 0; // expected-note 5 {{declared}}
[]() { return a; }; // expected-error {{variable 'a' cannot be implicitly captured in a lambda with no capture-default specified}} expected-note {{begins here}}
[&]() { return a; };
[=]() { return a; };
[=]() { int* b = &a; }; // expected-error {{cannot initialize a variable of type 'int *' with an rvalue of type 'const int *'}}
[=]() { return [&]() { return a; }; };
[]() { return [&]() { return a; }; }; // expected-error {{variable 'a' cannot be implicitly captured in a lambda with no capture-default specified}} expected-note {{lambda expression begins here}}
[]() { return ^{ return a; }; };// expected-error {{variable 'a' cannot be implicitly captured in a lambda with no capture-default specified}} expected-note {{lambda expression begins here}}
[]() { return [&a] { return a; }; }; // expected-error 2 {{variable 'a' cannot be implicitly captured in a lambda with no capture-default specified}} expected-note 2 {{lambda expression begins here}}
[=]() { return [&a] { return a; }; }; //
const int b = 2;
[]() { return b; };
union { // expected-note {{declared}}
int c;
float d;
};
d = 3;
[=]() { return c; }; // expected-error {{unnamed variable cannot be implicitly captured in a lambda expression}}
__block int e; // expected-note 3 {{declared}}
[&]() { return e; }; // expected-error {{__block variable 'e' cannot be captured in a lambda expression}}
[&e]() { return e; }; // expected-error 2 {{__block variable 'e' cannot be captured in a lambda expression}}
int f[10]; // expected-note {{declared}}
[&]() { return f[2]; };
(void) ^{ return []() { return f[2]; }; }; // expected-error {{variable 'f' cannot be implicitly captured in a lambda with no capture-default specified}} \
// expected-note{{lambda expression begins here}}
struct G { G(); G(G&); int a; }; // expected-note 6 {{not viable}}
G g;
[=]() { const G* gg = &g; return gg->a; };
[=]() { return [=]{ const G* gg = &g; return gg->a; }(); }; // expected-error {{no matching constructor for initialization of 'G'}}
(void)^{ return [=]{ const G* gg = &g; return gg->a; }(); }; // expected-error 2 {{no matching constructor for initialization of 'const G'}}
const int h = a; // expected-note {{declared}}
[]() { return h; }; // expected-error {{variable 'h' cannot be implicitly captured in a lambda with no capture-default specified}} expected-note {{lambda expression begins here}}
// References can appear in constant expressions if they are initialized by
// reference constant expressions.
int i;
int &ref_i = i; // expected-note {{declared}}
[] { return ref_i; }; // expected-error {{variable 'ref_i' cannot be implicitly captured in a lambda with no capture-default specified}} expected-note {{lambda expression begins here}}
static int j;
int &ref_j = j;
[] { return ref_j; }; // ok
}
}
namespace PR12031 {
struct X {
template<typename T>
X(const T&);
~X();
};
void f(int i, X x);
void g() {
const int v = 10;
f(v, [](){});
}
}
namespace NullPtr {
int &f(int *p);
char &f(...);
void g() {
int n = 0;
[=] {
char &k = f(n); // not a null pointer constant
} ();
const int m = 0;
[=] {
int &k = f(m); // expected-warning{{expression which evaluates to zero treated as a null pointer constant of type 'int *'}}
} ();
[=] () -> bool {
int &k = f(m); // expected-warning{{expression which evaluates to zero treated as a null pointer constant of type 'int *'}}
return &m == 0;
} ();
[m] {
int &k = f(m); // expected-warning{{expression which evaluates to zero treated as a null pointer constant of type 'int *'}}
} ();
}
}
void PR12248()
{
unsigned int result = 0;
auto l = [&]() { ++result; };
}
namespace ModifyingCapture {
void test() {
int n = 0;
[=] {
n = 1; // expected-error {{cannot assign to a variable captured by copy in a non-mutable lambda}}
};
}
}
namespace VariadicPackExpansion {
template<typename T, typename U> using Fst = T;
template<typename...Ts> bool g(Fst<bool, Ts> ...bools);
template<typename...Ts> bool f(Ts &&...ts) {
return g<Ts...>([&ts] {
if (!ts)
return false;
--ts;
return true;
} () ...);
}
void h() {
int a = 5, b = 2, c = 3;
while (f(a, b, c)) {
}
}
struct sink {
template<typename...Ts> sink(Ts &&...) {}
};
template<typename...Ts> void local_class() {
sink {
[] (Ts t) {
struct S : Ts {
void f(Ts t) {
Ts &that = *this;
that = t;
}
Ts g() { return *this; };
};
S s;
s.f(t);
return s;
} (Ts()).g() ...
};
};
struct X {}; struct Y {};
template void local_class<X, Y>();
template<typename...Ts> void nested(Ts ...ts) {
f(
// Each expansion of this lambda implicitly captures all of 'ts', because
// the inner lambda also expands 'ts'.
[&] {
return ts + [&] { return f(ts...); } ();
} () ...
);
}
template void nested(int, int, int);
template<typename...Ts> void nested2(Ts ...ts) { // expected-note 2{{here}}
// Capture all 'ts', use only one.
f([&ts...] { return ts; } ()...);
// Capture each 'ts', use it.
f([&ts] { return ts; } ()...);
// Capture all 'ts', use all of them.
f([&ts...] { return (int)f(ts...); } ());
// Capture each 'ts', use all of them. Ill-formed. In more detail:
//
// We instantiate two lambdas here; the first captures ts$0, the second
// captures ts$1. Both of them reference both ts parameters, so both are
// ill-formed because ts can't be implicitly captured.
//
// FIXME: This diagnostic does not explain what's happening. We should
// specify which 'ts' we're referring to in its diagnostic name. We should
// also say which slice of the pack expansion is being performed in the
// instantiation backtrace.
f([&ts] { return (int)f(ts...); } ()...); // \
// expected-error 2{{'ts' cannot be implicitly captured}} \
// expected-note 2{{lambda expression begins here}}
}
template void nested2(int); // ok
template void nested2(int, int); // expected-note {{in instantiation of}}
}
namespace PR13860 {
void foo() {
auto x = PR13860UndeclaredIdentifier(); // expected-error {{use of undeclared identifier 'PR13860UndeclaredIdentifier'}}
auto y = [x]() { };
static_assert(sizeof(y), "");
}
}
namespace PR13854 {
auto l = [](void){};
}
namespace PR14518 {
auto f = [](void) { return __func__; }; // no-warning
}
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