[libcxx][test] Silence nodiscard warnings for std::expected by StephanTLavavej · Pull Request #119174 · llvm/llvm-project (original) (raw)

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Author: Stephan T. Lavavej (StephanTLavavej)

Changes

I'm exploring marking microsoft/STL's std::expected as [[nodiscard]], which affects all functions returning std::expected, including its own monadic member functions.

As usual, libc++'s test suite contains calls to these member functions to make sure they compile, but it's discarding the returns. I'm adding (void) casts to silence the [[nodiscard]] warnings without altering what the test is covering.

Full diff: https://github.com/llvm/llvm-project/pull/119174.diff

4 Files Affected:

• (modified) libcxx/test/std/utilities/expected/expected.expected/monadic/and_then.pass.cpp (+8-8)
• (modified) libcxx/test/std/utilities/expected/expected.expected/monadic/or_else.pass.cpp (+10-10)
• (modified) libcxx/test/std/utilities/expected/expected.expected/monadic/transform.pass.cpp (+12-12)
• (modified) libcxx/test/std/utilities/expected/expected.expected/monadic/transform_error.pass.cpp (+10-10)

diff --git a/libcxx/test/std/utilities/expected/expected.expected/monadic/and_then.pass.cpp b/libcxx/test/std/utilities/expected/expected.expected/monadic/and_then.pass.cpp index 293c2d39d4a325..3ac58b34eff8c6 100644 --- a/libcxx/test/std/utilities/expected/expected.expected/monadic/and_then.pass.cpp +++ b/libcxx/test/std/utilities/expected/expected.expected/monadic/and_then.pass.cpp @@ -263,8 +263,8 @@ constexpr void test_val_types() { constexpr void test_sfinae() { std::expected<NonConst, int> e(std::unexpected(2)); auto l = [](auto&& x) { return x.non_const(); };

• e.and_then(l);
• std::move(e).and_then(l);

• (void)e.and_then(l);
• (void)std::move(e).and_then(l); }

constexpr void test_move_only_error_type() { @@ -272,14 +272,14 @@ constexpr void test_move_only_error_type() { { std::expected<int, MoveOnlyErrorType> e; auto l = { return std::expected<int, MoveOnlyErrorType>{}; };

• std::move(e).and_then(l);

• (void)std::move(e).and_then(l);

}

// Test const&& { const std::expected<int, MoveOnlyErrorType> e; auto l = [](const int) { return std::expected<int, MoveOnlyErrorType>{}; };

• std::move(e).and_then(l);

• (void)std::move(e).and_then(l);

} }

@@ -296,10 +296,10 @@ constexpr bool test() { return std::expected<int, int>(); };

• e.and_then(never_called);
• std::move(e).and_then(never_called);
• ce.and_then(never_called);
• std::move(ce).and_then(never_called);

• (void)e.and_then(never_called);

• (void)std::move(e).and_then(never_called);

• (void)ce.and_then(never_called);

• (void)std::move(ce).and_then(never_called);

  return true;

} diff --git a/libcxx/test/std/utilities/expected/expected.expected/monadic/or_else.pass.cpp b/libcxx/test/std/utilities/expected/expected.expected/monadic/or_else.pass.cpp index b472a2756be9f9..2587ca60a8efd2 100644 --- a/libcxx/test/std/utilities/expected/expected.expected/monadic/or_else.pass.cpp +++ b/libcxx/test/std/utilities/expected/expected.expected/monadic/or_else.pass.cpp @@ -178,8 +178,8 @@ struct NonConst { constexpr void test_sfinae() { std::expected<int, NonConst> e{1}; auto l = [](auto&& x) { return x.non_const(); };

• e.or_else(l);
• std::move(e).or_else(l);

• (void)e.or_else(l);
• (void)std::move(e).or_else(l); }

constexpr void test_move_only_error_type() { @@ -187,28 +187,28 @@ constexpr void test_move_only_error_type() { { std::expected<int, MoveOnlyErrorType> e; auto l = { return std::expected<int, int>{}; };

•  e.or_else(l);

•  (void)e.or_else(l);

  }

  // Test const& { const std::expected<int, MoveOnlyErrorType> e; auto l = [](const MoveOnlyErrorType&) { return std::expected<int, int>{}; };

•  e.or_else(l);

•  (void)e.or_else(l);

  }

  // Test && { std::expected<int, MoveOnlyErrorType> e; auto l = { return std::expected<int, int>{}; };

•  std::move(e).or_else(l);

•  (void)std::move(e).or_else(l);

  }

  // Test const&& { const std::expected<int, MoveOnlyErrorType> e; auto l = [](const MoveOnlyErrorType&&) { return std::expected<int, int>{}; };

•  std::move(e).or_else(l);

•  (void)std::move(e).or_else(l);

  } }

@@ -225,10 +225,10 @@ constexpr bool test() { return std::expected<int, int>(); };

• e.or_else(never_called);
• std::move(e).or_else(never_called);
• ce.or_else(never_called);
• std::move(ce).or_else(never_called);

• (void)e.or_else(never_called);
• (void)std::move(e).or_else(never_called);
• (void)ce.or_else(never_called);
• (void)std::move(ce).or_else(never_called); return true; }

diff --git a/libcxx/test/std/utilities/expected/expected.expected/monadic/transform.pass.cpp b/libcxx/test/std/utilities/expected/expected.expected/monadic/transform.pass.cpp index 4fb21374aebe31..d7718205113d0b 100644 --- a/libcxx/test/std/utilities/expected/expected.expected/monadic/transform.pass.cpp +++ b/libcxx/test/std/utilities/expected/expected.expected/monadic/transform.pass.cpp @@ -187,13 +187,13 @@ constexpr void test_val_types() { constexpr void test_take_val_return_void() { std::expected<int, int> e(1); int val = 0;

• e.transform([&val](T&&) -> void {

• (void)e.transform([&val](T&&) -> void { static_assert(std::is_same_v<T, int&>); assert(val == 0); val = 1; }); assert(val == 1);

• std::move(e).transform([&val](T&&) -> void {

• (void)std::move(e).transform([&val](T&&) -> void { static_assert(std::is_same_v<T, int>); assert(val == 1); val = 2; @@ -201,13 +201,13 @@ constexpr void test_take_val_return_void() {

  const auto& ce = e; assert(val == 2);

• ce.transform([&val](T&&) -> void {

• (void)ce.transform([&val](T&&) -> void { static_assert(std::is_same_v<T, const int&>); assert(val == 2); val = 3; }); assert(val == 3);

• std::move(ce).transform([&val](T&&) -> void {

• (void)std::move(ce).transform([&val](T&&) -> void { static_assert(std::is_same_v<T, const int>); assert(val == 3); val = 4; @@ -227,8 +227,8 @@ constexpr void test_direct_non_list_init() { constexpr void test_sfinae() { std::expected<NonConst, int> e(std::unexpected(2)); auto l = [](auto&& x) { return x.non_const(); };

• e.transform(l);
• std::move(e).transform(l);

• (void)e.transform(l);

• (void)std::move(e).transform(l);

  std::expected<int, int> e1(std::unexpected(1)); const auto& ce1 = e1;

@@ -237,10 +237,10 @@ constexpr void test_sfinae() { return std::expected<int, int>(); };

• e1.transform(never_called);
• std::move(e1).transform(never_called);
• ce1.and_then(never_called);
• std::move(ce1).transform(never_called);

• (void)e1.transform(never_called);
• (void)std::move(e1).transform(never_called);
• (void)ce1.and_then(never_called);
• (void)std::move(ce1).transform(never_called); }

constexpr void test_move_only_error_type() { @@ -248,14 +248,14 @@ constexpr void test_move_only_error_type() { { std::expected<int, MoveOnlyErrorType> e; auto l = { return 0; };

•  std::move(e).transform(l);

•  (void)std::move(e).transform(l);

  }

  // Test const&& { const std::expected<int, MoveOnlyErrorType> e; auto l = [](const int) { return 0; };

•  std::move(e).transform(l);

•  (void)std::move(e).transform(l);

  } }

diff --git a/libcxx/test/std/utilities/expected/expected.expected/monadic/transform_error.pass.cpp b/libcxx/test/std/utilities/expected/expected.expected/monadic/transform_error.pass.cpp index d35788d9fef25e..a19e17b01f6a94 100644 --- a/libcxx/test/std/utilities/expected/expected.expected/monadic/transform_error.pass.cpp +++ b/libcxx/test/std/utilities/expected/expected.expected/monadic/transform_error.pass.cpp @@ -197,8 +197,8 @@ constexpr void test_direct_non_list_init() { constexpr void test_sfinae() { std::expected<int, NonConst> e(2); auto l = [](auto&& x) { return x.non_const(); };

• e.transform_error(l);
• std::move(e).transform_error(l);

• (void)e.transform_error(l);

• (void)std::move(e).transform_error(l);

  std::expected<int, int> e1; const auto& ce1 = e1;

@@ -208,10 +208,10 @@ constexpr void test_sfinae() { return 0; };

• e1.transform_error(never_called);
• std::move(e1).transform_error(never_called);
• ce1.transform_error(never_called);
• std::move(ce1).transform_error(never_called);

• (void)e1.transform_error(never_called);
• (void)std::move(e1).transform_error(never_called);
• (void)ce1.transform_error(never_called);
• (void)std::move(ce1).transform_error(never_called); }

constexpr void test_move_only_error_type() { @@ -219,28 +219,28 @@ constexpr void test_move_only_error_type() { { std::expected<int, MoveOnlyErrorType> e; auto l = { return 0; };

•  e.transform_error(l);

•  (void)e.transform_error(l);

  }

  // Test const& { const std::expected<int, MoveOnlyErrorType> e; auto l = [](const MoveOnlyErrorType&) { return 0; };

•  e.transform_error(l);

•  (void)e.transform_error(l);

  }

  // Test && { std::expected<int, MoveOnlyErrorType> e; auto l = { return 0; };

•  std::move(e).transform_error(l);

•  (void)std::move(e).transform_error(l);

  }

  // Test const&& { const std::expected<int, MoveOnlyErrorType> e; auto l = [](const MoveOnlyErrorType&&) { return 0; };

•  std::move(e).transform_error(l);

•  (void)std::move(e).transform_error(l);

  } }