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feat: recognize requires expressions
1 parent ccf7011 commit 698b44c

22 files changed

+870
-37
lines changed

‎regression-tests/pure2-concept-definition-no-pitfall-1.cpp2

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// https://youtu.be/CXn02MPkn8Y?t=2337
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negatable: <T> concept = requires(t: T)
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{
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_ = -t is T; // Hopefully obviously wrong. Should be `{ -t } is T;`.
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};
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main: () = static_assert(negatable<char>);

‎regression-tests/pure2-concept-definition-no-pitfall-2.cpp2

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// https://youtu.be/CXn02MPkn8Y?t=2418
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int_sized: <T> concept = requires(t: T)
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{
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_ = sizeof(T) == 4; // Hopefully obviously wrong. Should be `requires (sizeof(T) == 4);`.
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};
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// Could also be `int_sized: <T> concept = sizeof(T) == 4;`.
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main: () = static_assert(int_sized<char>);

‎regression-tests/pure2-concept-definition-no-pitfall-3.cpp2

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// https://youtu.be/CXn02MPkn8Y?t=2455
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nothrow_incrementable: <T> concept = requires(inout t: T)
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{
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_ = noexcept(t++); // Hopefully obviously wrong. Should be `requires noexcept(t++);` or `{ t++ } !throws;`.
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};
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main: () = { static_assert(nothrow_incrementable<char>); }

‎regression-tests/pure2-concept-definition-pit-of-success-1.cpp2

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// https://quuxplusone.github.io/blog/2021/06/09/another-concepts-chest-mimic/
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has_a_but_not_b: <T> concept = requires(t: T)
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{
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_ = a(t);
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!requires _ = b(t); // In Cpp2, this works and does the correct thing.
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};
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s1: @struct type = { }
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s2: @struct type = { }
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a: (_: s2) = { }
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s3: @struct type = { }
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b: (_: s3) = { }
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s4: @struct type = { }
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a: (_: s4) = { }
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b: (_: s4) = { }
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main: () = {
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static_assert(!has_a_but_not_b<s1>); // as expected
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static_assert(has_a_but_not_b<s2>); // as expected
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static_assert(!has_a_but_not_b<s3>); // as expected
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static_assert(!has_a_but_not_b<s4>); // pit of success!
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}

‎regression-tests/pure2-concept-definition.cpp2

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@@ -1,5 +1,29 @@
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arithmetic: <T> concept = std::integral<T> || std::floating_point<T>;
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main: () = {
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assert<testing>( arithmetic<i32> );
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assert<testing>( arithmetic<float> );
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number_difference_t: <T> type == std::type_identity_t<decltype(T() - T())>;
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number: <T> concept = std::regular<T> && requires(c: T)
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{
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!requires std::iter_reference_t<T>; // Negative requirement.
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{c + c} is std::common_with<T>; // Compound requirement.
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number_difference_t<T>; // Type requirement.
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_ = c - c; // Expression requirement.
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requires std::common_with<number_difference_t<T>, T>; // Nested requirement.
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};
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test_nonthrowing_requirements: <T> concept = requires
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{ // clang-format off
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{ T() } !throws;
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{ -T() } !throws, is std::same_as<T>;
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}; // clang-format on
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main: () = {
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static_assert(arithmetic<i32>);
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static_assert(arithmetic<float>);
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static_assert(number<i32>);
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static_assert(number<float>);
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static_assert(number<std::chrono::seconds>);
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static_assert(!number<* i32>);
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static_assert(!number<std::reverse_iterator<* i32>>);
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static_assert(test_nonthrowing_requirements<i32>);
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static_assert(!test_nonthrowing_requirements<std::chrono::seconds>);
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}

‎regression-tests/pure2-print.cpp2

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@@ -87,6 +87,19 @@ outer: @print type = {
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is 43 = "forty-and-three";
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is _ = "default case";
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} << "\n";
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_ =
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requires { std::vector<int>; }
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+ requires { _ = 0; }
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+ requires {
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requires true;
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!requires std::vector<int>;
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!requires _ = 0;
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{ 0 };
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{ 0 } !throws;
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{ 0 } is std::regular;
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{ 0 } !throws, is std::regular;
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};
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}
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x: <Ts...: type> type = {

‎regression-tests/pure2-requires-clauses.cpp2

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@@ -19,6 +19,8 @@ f: (x) -> int requires true == x;
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v: <T> const T requires std::same_as<T, i32> = 0;
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g: <T> () requires true = { }
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main: () = {
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_: X<int,int> = ();
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std::cout << f<int,int>(2,5)

‎regression-tests/test-results/pure2-concept-definition-no-pitfall-1.cpp

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#define CPP2_IMPORT_STD Yes
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//=== Cpp2 type declarations ====================================================
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#include "cpp2util.h"
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#line 1 "pure2-concept-definition-no-pitfall-1.cpp2"
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//=== Cpp2 type definitions and function declarations ===========================
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#line 1 "pure2-concept-definition-no-pitfall-1.cpp2"
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// https://youtu.be/CXn02MPkn8Y?t=2337
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#line 2 "pure2-concept-definition-no-pitfall-1.cpp2"
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template<typename T> concept negatable = requires(T const& t) {
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cpp2::impl::is<T>(-t);
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}; // Hopefully obviously wrong. Should be `{ -t } is T;`.
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auto main() -> int;
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//=== Cpp2 function definitions =================================================
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#line 1 "pure2-concept-definition-no-pitfall-1.cpp2"
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#line 7 "pure2-concept-definition-no-pitfall-1.cpp2"
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auto main() -> int { static_assert(negatable<char>); }
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‎regression-tests/test-results/pure2-concept-definition-no-pitfall-1.cpp2.output

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pure2-concept-definition-no-pitfall-1.cpp2... ok (all Cpp2, passes safety checks)
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‎regression-tests/test-results/pure2-concept-definition-no-pitfall-2.cpp

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#define CPP2_IMPORT_STD Yes
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//=== Cpp2 type declarations ====================================================
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#include "cpp2util.h"
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#line 1 "pure2-concept-definition-no-pitfall-2.cpp2"
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//=== Cpp2 type definitions and function declarations ===========================
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#line 1 "pure2-concept-definition-no-pitfall-2.cpp2"
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// https://youtu.be/CXn02MPkn8Y?t=2418
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#line 2 "pure2-concept-definition-no-pitfall-2.cpp2"
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template<typename T> concept int_sized = requires(T const& t) {
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sizeof(T) == 4;
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}; // Hopefully obviously wrong. Should be `requires (sizeof(T) == 4);`.
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// Could also be `int_sized: <T> concept = sizeof(T) == 4;`.
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auto main() -> int;
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//=== Cpp2 function definitions =================================================
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#line 1 "pure2-concept-definition-no-pitfall-2.cpp2"
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#line 8 "pure2-concept-definition-no-pitfall-2.cpp2"
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auto main() -> int { static_assert(int_sized<char>); }
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‎regression-tests/test-results/pure2-concept-definition-no-pitfall-2.cpp2.output

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pure2-concept-definition-no-pitfall-2.cpp2... ok (all Cpp2, passes safety checks)
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‎regression-tests/test-results/pure2-concept-definition-no-pitfall-3.cpp

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#define CPP2_IMPORT_STD Yes
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//=== Cpp2 type declarations ====================================================
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#include "cpp2util.h"
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#line 1 "pure2-concept-definition-no-pitfall-3.cpp2"
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//=== Cpp2 type definitions and function declarations ===========================
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#line 1 "pure2-concept-definition-no-pitfall-3.cpp2"
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// https://youtu.be/CXn02MPkn8Y?t=2455
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#line 2 "pure2-concept-definition-no-pitfall-3.cpp2"
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template<typename T> concept nothrow_incrementable = requires(T& t) {
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noexcept(++t);
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}; // Hopefully obviously wrong. Should be `requires noexcept(t++);` or `{ t++ } !throws;`.
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auto main() -> int;
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//=== Cpp2 function definitions =================================================
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#line 1 "pure2-concept-definition-no-pitfall-3.cpp2"
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#line 7 "pure2-concept-definition-no-pitfall-3.cpp2"
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auto main() -> int{static_assert(nothrow_incrementable<char>); }
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‎regression-tests/test-results/pure2-concept-definition-no-pitfall-3.cpp2.output

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pure2-concept-definition-no-pitfall-3.cpp2... ok (all Cpp2, passes safety checks)
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‎regression-tests/test-results/pure2-concept-definition-pit-of-success-1.cpp

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#define CPP2_IMPORT_STD Yes
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//=== Cpp2 type declarations ====================================================
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#include "cpp2util.h"
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#line 1 "pure2-concept-definition-pit-of-success-1.cpp2"
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#line 8 "pure2-concept-definition-pit-of-success-1.cpp2"
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class s1;
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class s2;
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class s3;
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class s4;
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//=== Cpp2 type definitions and function declarations ===========================
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#line 1 "pure2-concept-definition-pit-of-success-1.cpp2"
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// https://quuxplusone.github.io/blog/2021/06/09/another-concepts-chest-mimic/
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#line 2 "pure2-concept-definition-pit-of-success-1.cpp2"
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template<typename T> concept has_a_but_not_b = requires(T const& t) {
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a(t);
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requires !requires { b(t); };
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}; // In Cpp2, this works and does the correct thing.
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class s1 {};
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class s2 {};
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auto a([[maybe_unused]] cpp2::impl::in<s2> unnamed_param_1) -> void;
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class s3 {};
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auto b([[maybe_unused]] cpp2::impl::in<s3> unnamed_param_1) -> void;
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class s4 {};
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auto a([[maybe_unused]] cpp2::impl::in<s4> unnamed_param_1) -> void;
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auto b([[maybe_unused]] cpp2::impl::in<s4> unnamed_param_1) -> void;
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auto main() -> int;
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//=== Cpp2 function definitions =================================================
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#line 1 "pure2-concept-definition-pit-of-success-1.cpp2"
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#line 10 "pure2-concept-definition-pit-of-success-1.cpp2"
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auto a([[maybe_unused]] cpp2::impl::in<s2> unnamed_param_1) -> void{}
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#line 12 "pure2-concept-definition-pit-of-success-1.cpp2"
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auto b([[maybe_unused]] cpp2::impl::in<s3> unnamed_param_1) -> void{}
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#line 14 "pure2-concept-definition-pit-of-success-1.cpp2"
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auto a([[maybe_unused]] cpp2::impl::in<s4> unnamed_param_1) -> void{}
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#line 15 "pure2-concept-definition-pit-of-success-1.cpp2"
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auto b([[maybe_unused]] cpp2::impl::in<s4> unnamed_param_1) -> void{}
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#line 17 "pure2-concept-definition-pit-of-success-1.cpp2"
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auto main() -> int{
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static_assert(!(has_a_but_not_b<s1>));// as expected
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static_assert(has_a_but_not_b<s2>); // as expected
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static_assert(!(has_a_but_not_b<s3>));// as expected
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static_assert(!(has_a_but_not_b<s4>));// pit of success!
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}
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‎regression-tests/test-results/pure2-concept-definition-pit-of-success-1.cpp2.output

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pure2-concept-definition-pit-of-success-1.cpp2... ok (all Cpp2, passes safety checks)
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‎regression-tests/test-results/pure2-concept-definition.cpp

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#line 1 "pure2-concept-definition.cpp2"
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template<typename T> concept arithmetic = std::integral<T> || std::floating_point<T>;
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#line 2 "pure2-concept-definition.cpp2"
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#line 3 "pure2-concept-definition.cpp2"
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template<typename T> using number_difference_t = std::type_identity_t<decltype(T() - T())>;
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template<typename T> concept number = std::regular<T> && requires(T const& c) {
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requires !requires { typename std::iter_reference_t<T>; };// Negative requirement.
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{ c + c } -> std::common_with<T>; // Compound requirement.
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typename number_difference_t<T>; // Type requirement.
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c - c; // Expression requirement.
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requires std::common_with<number_difference_t<T>,T>;
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}; // Nested requirement.
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template<typename T> concept test_nonthrowing_requirements = requires {
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// clang-format off
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{ T() } noexcept;
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{ -T() } noexcept -> std::same_as<T>;
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}; // clang-format on
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auto main() -> int;
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//=== Cpp2 function definitions =================================================
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#line 1 "pure2-concept-definition.cpp2"
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#line 2 "pure2-concept-definition.cpp2"
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auto main() -> int {
25-
if (cpp2::testing.is_active() && !(arithmetic<cpp2::i32>) ) { cpp2::testing.report_violation(""); }
26-
if (cpp2::testing.is_active() && !(arithmetic<float>) ) { cpp2::testing.report_violation(""); }
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#line 19 "pure2-concept-definition.cpp2"
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auto main() -> int{
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static_assert(arithmetic<cpp2::i32>);
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static_assert(arithmetic<float>);
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static_assert(number<cpp2::i32>);
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static_assert(number<float>);
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static_assert(number<std::chrono::seconds>);
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static_assert(!(number<cpp2::i32*>));
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static_assert(!(number<std::reverse_iterator<cpp2::i32*>>));
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static_assert(test_nonthrowing_requirements<cpp2::i32>);
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static_assert(!(test_nonthrowing_requirements<std::chrono::seconds>));
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}
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