[libc++][string_view] Applied [[nodiscard]] (#169010)

`[[nodiscard]]` should be applied to functions where discarding the
return value is most likely a correctness issue.
- https://libcxx.llvm.org/CodingGuidelines.html#apply-nodiscard-where-relevant
This commit is contained in:
Hristo Hristov
2025-11-24 18:44:44 +02:00
committed by GitHub
parent cc0371f2a4
commit e3d0ac1886
3 changed files with 211 additions and 68 deletions

View File

@@ -362,11 +362,11 @@ public:
# endif
// [string.view.iterators], iterators
_LIBCPP_CONSTEXPR _LIBCPP_HIDE_FROM_ABI const_iterator begin() const _NOEXCEPT { return cbegin(); }
[[__nodiscard__]] _LIBCPP_CONSTEXPR _LIBCPP_HIDE_FROM_ABI const_iterator begin() const _NOEXCEPT { return cbegin(); }
_LIBCPP_CONSTEXPR _LIBCPP_HIDE_FROM_ABI const_iterator end() const _NOEXCEPT { return cend(); }
[[__nodiscard__]] _LIBCPP_CONSTEXPR _LIBCPP_HIDE_FROM_ABI const_iterator end() const _NOEXCEPT { return cend(); }
_LIBCPP_CONSTEXPR _LIBCPP_HIDE_FROM_ABI const_iterator cbegin() const _NOEXCEPT {
[[__nodiscard__]] _LIBCPP_CONSTEXPR _LIBCPP_HIDE_FROM_ABI const_iterator cbegin() const _NOEXCEPT {
# ifdef _LIBCPP_ABI_BOUNDED_ITERATORS
return std::__make_bounded_iter(data(), data(), data() + size());
# else
@@ -374,7 +374,7 @@ public:
# endif
}
_LIBCPP_CONSTEXPR _LIBCPP_HIDE_FROM_ABI const_iterator cend() const _NOEXCEPT {
[[__nodiscard__]] _LIBCPP_CONSTEXPR _LIBCPP_HIDE_FROM_ABI const_iterator cend() const _NOEXCEPT {
# ifdef _LIBCPP_ABI_BOUNDED_ITERATORS
return std::__make_bounded_iter(data() + size(), data(), data() + size());
# else
@@ -382,51 +382,54 @@ public:
# endif
}
_LIBCPP_CONSTEXPR_SINCE_CXX17 _LIBCPP_HIDE_FROM_ABI const_reverse_iterator rbegin() const _NOEXCEPT {
[[__nodiscard__]] _LIBCPP_CONSTEXPR_SINCE_CXX17 _LIBCPP_HIDE_FROM_ABI const_reverse_iterator
rbegin() const _NOEXCEPT {
return const_reverse_iterator(cend());
}
_LIBCPP_CONSTEXPR_SINCE_CXX17 _LIBCPP_HIDE_FROM_ABI const_reverse_iterator rend() const _NOEXCEPT {
[[__nodiscard__]] _LIBCPP_CONSTEXPR_SINCE_CXX17 _LIBCPP_HIDE_FROM_ABI const_reverse_iterator rend() const _NOEXCEPT {
return const_reverse_iterator(cbegin());
}
_LIBCPP_CONSTEXPR_SINCE_CXX17 _LIBCPP_HIDE_FROM_ABI const_reverse_iterator crbegin() const _NOEXCEPT {
[[__nodiscard__]] _LIBCPP_CONSTEXPR_SINCE_CXX17 _LIBCPP_HIDE_FROM_ABI const_reverse_iterator
crbegin() const _NOEXCEPT {
return const_reverse_iterator(cend());
}
_LIBCPP_CONSTEXPR_SINCE_CXX17 _LIBCPP_HIDE_FROM_ABI const_reverse_iterator crend() const _NOEXCEPT {
[[__nodiscard__]] _LIBCPP_CONSTEXPR_SINCE_CXX17 _LIBCPP_HIDE_FROM_ABI const_reverse_iterator crend() const _NOEXCEPT {
return const_reverse_iterator(cbegin());
}
// [string.view.capacity], capacity
_LIBCPP_CONSTEXPR _LIBCPP_HIDE_FROM_ABI size_type size() const _NOEXCEPT { return __size_; }
[[__nodiscard__]] _LIBCPP_CONSTEXPR _LIBCPP_HIDE_FROM_ABI size_type size() const _NOEXCEPT { return __size_; }
_LIBCPP_CONSTEXPR _LIBCPP_HIDE_FROM_ABI size_type length() const _NOEXCEPT { return __size_; }
[[__nodiscard__]] _LIBCPP_CONSTEXPR _LIBCPP_HIDE_FROM_ABI size_type length() const _NOEXCEPT { return __size_; }
_LIBCPP_CONSTEXPR _LIBCPP_HIDE_FROM_ABI size_type max_size() const _NOEXCEPT {
[[__nodiscard__]] _LIBCPP_CONSTEXPR _LIBCPP_HIDE_FROM_ABI size_type max_size() const _NOEXCEPT {
return numeric_limits<size_type>::max() / sizeof(value_type);
}
[[__nodiscard__]] _LIBCPP_HIDE_FROM_ABI _LIBCPP_CONSTEXPR bool empty() const _NOEXCEPT { return __size_ == 0; }
// [string.view.access], element access
_LIBCPP_CONSTEXPR _LIBCPP_HIDE_FROM_ABI const_reference operator[](size_type __pos) const _NOEXCEPT {
[[__nodiscard__]] _LIBCPP_CONSTEXPR _LIBCPP_HIDE_FROM_ABI const_reference
operator[](size_type __pos) const _NOEXCEPT {
return _LIBCPP_ASSERT_VALID_ELEMENT_ACCESS(__pos < size(), "string_view[] index out of bounds"), __data_[__pos];
}
_LIBCPP_CONSTEXPR _LIBCPP_HIDE_FROM_ABI const_reference at(size_type __pos) const {
[[__nodiscard__]] _LIBCPP_CONSTEXPR _LIBCPP_HIDE_FROM_ABI const_reference at(size_type __pos) const {
return __pos >= size() ? (__throw_out_of_range("string_view::at"), __data_[0]) : __data_[__pos];
}
_LIBCPP_CONSTEXPR _LIBCPP_HIDE_FROM_ABI const_reference front() const _NOEXCEPT {
[[__nodiscard__]] _LIBCPP_CONSTEXPR _LIBCPP_HIDE_FROM_ABI const_reference front() const _NOEXCEPT {
return _LIBCPP_ASSERT_VALID_ELEMENT_ACCESS(!empty(), "string_view::front(): string is empty"), __data_[0];
}
_LIBCPP_CONSTEXPR _LIBCPP_HIDE_FROM_ABI const_reference back() const _NOEXCEPT {
[[__nodiscard__]] _LIBCPP_CONSTEXPR _LIBCPP_HIDE_FROM_ABI const_reference back() const _NOEXCEPT {
return _LIBCPP_ASSERT_VALID_ELEMENT_ACCESS(!empty(), "string_view::back(): string is empty"), __data_[__size_ - 1];
}
_LIBCPP_CONSTEXPR _LIBCPP_HIDE_FROM_ABI const_pointer data() const _NOEXCEPT { return __data_; }
[[__nodiscard__]] _LIBCPP_CONSTEXPR _LIBCPP_HIDE_FROM_ABI const_pointer data() const _NOEXCEPT { return __data_; }
// [string.view.modifiers], modifiers:
_LIBCPP_CONSTEXPR_SINCE_CXX14 _LIBCPP_HIDE_FROM_ABI void remove_prefix(size_type __n) _NOEXCEPT {
@@ -459,7 +462,8 @@ public:
return __rlen;
}
_LIBCPP_CONSTEXPR _LIBCPP_HIDE_FROM_ABI basic_string_view substr(size_type __pos = 0, size_type __n = npos) const {
[[__nodiscard__]] _LIBCPP_CONSTEXPR _LIBCPP_HIDE_FROM_ABI basic_string_view
substr(size_type __pos = 0, size_type __n = npos) const {
// Use the `__assume_valid` form of the constructor to avoid an unnecessary check. Any substring of a view is a
// valid view. In particular, `size()` is known to be smaller than `numeric_limits<difference_type>::max()`, so the
// new size is also smaller. See also https://llvm.org/PR91634.
@@ -474,7 +478,7 @@ public:
}
# endif
_LIBCPP_CONSTEXPR_SINCE_CXX14 int compare(basic_string_view __sv) const _NOEXCEPT {
[[__nodiscard__]] _LIBCPP_CONSTEXPR_SINCE_CXX14 int compare(basic_string_view __sv) const _NOEXCEPT {
size_type __rlen = std::min(size(), __sv.size());
int __retval = _Traits::compare(data(), __sv.data(), __rlen);
if (__retval == 0) // first __rlen chars matched
@@ -482,50 +486,51 @@ public:
return __retval;
}
_LIBCPP_CONSTEXPR_SINCE_CXX14 _LIBCPP_HIDE_FROM_ABI int
[[__nodiscard__]] _LIBCPP_CONSTEXPR_SINCE_CXX14 _LIBCPP_HIDE_FROM_ABI int
compare(size_type __pos1, size_type __n1, basic_string_view __sv) const {
return substr(__pos1, __n1).compare(__sv);
}
_LIBCPP_CONSTEXPR_SINCE_CXX14 _LIBCPP_HIDE_FROM_ABI int
[[__nodiscard__]] _LIBCPP_CONSTEXPR_SINCE_CXX14 _LIBCPP_HIDE_FROM_ABI int
compare(size_type __pos1, size_type __n1, basic_string_view __sv, size_type __pos2, size_type __n2) const {
return substr(__pos1, __n1).compare(__sv.substr(__pos2, __n2));
}
_LIBCPP_CONSTEXPR_SINCE_CXX14 _LIBCPP_HIDE_FROM_ABI int
[[__nodiscard__]] _LIBCPP_CONSTEXPR_SINCE_CXX14 _LIBCPP_HIDE_FROM_ABI int
compare(const _CharT* _LIBCPP_DIAGNOSE_NULLPTR __s) const _NOEXCEPT {
return compare(basic_string_view(__s));
}
_LIBCPP_CONSTEXPR_SINCE_CXX14 _LIBCPP_HIDE_FROM_ABI int
[[__nodiscard__]] _LIBCPP_CONSTEXPR_SINCE_CXX14 _LIBCPP_HIDE_FROM_ABI int
compare(size_type __pos1, size_type __n1, const _CharT* _LIBCPP_DIAGNOSE_NULLPTR __s) const {
return substr(__pos1, __n1).compare(basic_string_view(__s));
}
_LIBCPP_CONSTEXPR_SINCE_CXX14 _LIBCPP_HIDE_FROM_ABI int
[[__nodiscard__]] _LIBCPP_CONSTEXPR_SINCE_CXX14 _LIBCPP_HIDE_FROM_ABI int
compare(size_type __pos1, size_type __n1, const _CharT* __s, size_type __n2) const
_LIBCPP_DIAGNOSE_NULLPTR_IF(__n2 != 0 && __s == nullptr, " if n2 is not zero") {
return substr(__pos1, __n1).compare(basic_string_view(__s, __n2));
}
// find
_LIBCPP_CONSTEXPR_SINCE_CXX14 _LIBCPP_HIDE_FROM_ABI size_type
[[__nodiscard__]] _LIBCPP_CONSTEXPR_SINCE_CXX14 _LIBCPP_HIDE_FROM_ABI size_type
find(basic_string_view __s, size_type __pos = 0) const _NOEXCEPT {
return std::__str_find<value_type, size_type, traits_type, npos>(data(), size(), __s.data(), __pos, __s.size());
}
_LIBCPP_CONSTEXPR_SINCE_CXX14 _LIBCPP_HIDE_FROM_ABI size_type find(_CharT __c, size_type __pos = 0) const _NOEXCEPT {
[[__nodiscard__]] _LIBCPP_CONSTEXPR_SINCE_CXX14 _LIBCPP_HIDE_FROM_ABI size_type
find(_CharT __c, size_type __pos = 0) const _NOEXCEPT {
return std::__str_find<value_type, size_type, traits_type, npos>(data(), size(), __c, __pos);
}
_LIBCPP_CONSTEXPR_SINCE_CXX14 _LIBCPP_HIDE_FROM_ABI size_type
[[__nodiscard__]] _LIBCPP_CONSTEXPR_SINCE_CXX14 _LIBCPP_HIDE_FROM_ABI size_type
find(const _CharT* __s, size_type __pos, size_type __n) const _NOEXCEPT
_LIBCPP_DIAGNOSE_NULLPTR_IF(__n != 0 && __s == nullptr, " if n is not zero") {
_LIBCPP_ASSERT_NON_NULL(__n == 0 || __s != nullptr, "string_view::find(): received nullptr");
return std::__str_find<value_type, size_type, traits_type, npos>(data(), size(), __s, __pos, __n);
}
_LIBCPP_CONSTEXPR_SINCE_CXX14 _LIBCPP_HIDE_FROM_ABI size_type
[[__nodiscard__]] _LIBCPP_CONSTEXPR_SINCE_CXX14 _LIBCPP_HIDE_FROM_ABI size_type
find(const _CharT* _LIBCPP_DIAGNOSE_NULLPTR __s, size_type __pos = 0) const _NOEXCEPT {
_LIBCPP_ASSERT_NON_NULL(__s != nullptr, "string_view::find(): received nullptr");
return std::__str_find<value_type, size_type, traits_type, npos>(
@@ -533,24 +538,24 @@ public:
}
// rfind
_LIBCPP_CONSTEXPR_SINCE_CXX14 _LIBCPP_HIDE_FROM_ABI size_type
[[__nodiscard__]] _LIBCPP_CONSTEXPR_SINCE_CXX14 _LIBCPP_HIDE_FROM_ABI size_type
rfind(basic_string_view __s, size_type __pos = npos) const _NOEXCEPT {
return std::__str_rfind<value_type, size_type, traits_type, npos>(data(), size(), __s.data(), __pos, __s.size());
}
_LIBCPP_CONSTEXPR_SINCE_CXX14 _LIBCPP_HIDE_FROM_ABI size_type
[[__nodiscard__]] _LIBCPP_CONSTEXPR_SINCE_CXX14 _LIBCPP_HIDE_FROM_ABI size_type
rfind(_CharT __c, size_type __pos = npos) const _NOEXCEPT {
return std::__str_rfind<value_type, size_type, traits_type, npos>(data(), size(), __c, __pos);
}
_LIBCPP_CONSTEXPR_SINCE_CXX14 _LIBCPP_HIDE_FROM_ABI size_type
[[__nodiscard__]] _LIBCPP_CONSTEXPR_SINCE_CXX14 _LIBCPP_HIDE_FROM_ABI size_type
rfind(const _CharT* __s, size_type __pos, size_type __n) const _NOEXCEPT
_LIBCPP_DIAGNOSE_NULLPTR_IF(__n != 0 && __s == nullptr, " if n is not zero") {
_LIBCPP_ASSERT_NON_NULL(__n == 0 || __s != nullptr, "string_view::rfind(): received nullptr");
return std::__str_rfind<value_type, size_type, traits_type, npos>(data(), size(), __s, __pos, __n);
}
_LIBCPP_CONSTEXPR_SINCE_CXX14 _LIBCPP_HIDE_FROM_ABI size_type
[[__nodiscard__]] _LIBCPP_CONSTEXPR_SINCE_CXX14 _LIBCPP_HIDE_FROM_ABI size_type
rfind(const _CharT* _LIBCPP_DIAGNOSE_NULLPTR __s, size_type __pos = npos) const _NOEXCEPT {
_LIBCPP_ASSERT_NON_NULL(__s != nullptr, "string_view::rfind(): received nullptr");
return std::__str_rfind<value_type, size_type, traits_type, npos>(
@@ -558,25 +563,25 @@ public:
}
// find_first_of
_LIBCPP_CONSTEXPR_SINCE_CXX14 _LIBCPP_HIDE_FROM_ABI size_type
[[__nodiscard__]] _LIBCPP_CONSTEXPR_SINCE_CXX14 _LIBCPP_HIDE_FROM_ABI size_type
find_first_of(basic_string_view __s, size_type __pos = 0) const _NOEXCEPT {
return std::__str_find_first_of<value_type, size_type, traits_type, npos>(
data(), size(), __s.data(), __pos, __s.size());
}
_LIBCPP_CONSTEXPR_SINCE_CXX14 _LIBCPP_HIDE_FROM_ABI size_type
[[__nodiscard__]] _LIBCPP_CONSTEXPR_SINCE_CXX14 _LIBCPP_HIDE_FROM_ABI size_type
find_first_of(_CharT __c, size_type __pos = 0) const _NOEXCEPT {
return find(__c, __pos);
}
_LIBCPP_CONSTEXPR_SINCE_CXX14 _LIBCPP_HIDE_FROM_ABI size_type
[[__nodiscard__]] _LIBCPP_CONSTEXPR_SINCE_CXX14 _LIBCPP_HIDE_FROM_ABI size_type
find_first_of(const _CharT* __s, size_type __pos, size_type __n) const _NOEXCEPT
_LIBCPP_DIAGNOSE_NULLPTR_IF(__n != 0 && __s == nullptr, " if n is not zero") {
_LIBCPP_ASSERT_NON_NULL(__n == 0 || __s != nullptr, "string_view::find_first_of(): received nullptr");
return std::__str_find_first_of<value_type, size_type, traits_type, npos>(data(), size(), __s, __pos, __n);
}
_LIBCPP_CONSTEXPR_SINCE_CXX14 _LIBCPP_HIDE_FROM_ABI size_type
[[__nodiscard__]] _LIBCPP_CONSTEXPR_SINCE_CXX14 _LIBCPP_HIDE_FROM_ABI size_type
find_first_of(const _CharT* _LIBCPP_DIAGNOSE_NULLPTR __s, size_type __pos = 0) const _NOEXCEPT {
_LIBCPP_ASSERT_NON_NULL(__s != nullptr, "string_view::find_first_of(): received nullptr");
return std::__str_find_first_of<value_type, size_type, traits_type, npos>(
@@ -584,25 +589,25 @@ public:
}
// find_last_of
_LIBCPP_CONSTEXPR_SINCE_CXX14 _LIBCPP_HIDE_FROM_ABI size_type
[[__nodiscard__]] _LIBCPP_CONSTEXPR_SINCE_CXX14 _LIBCPP_HIDE_FROM_ABI size_type
find_last_of(basic_string_view __s, size_type __pos = npos) const _NOEXCEPT {
return std::__str_find_last_of<value_type, size_type, traits_type, npos>(
data(), size(), __s.data(), __pos, __s.size());
}
_LIBCPP_CONSTEXPR_SINCE_CXX14 _LIBCPP_HIDE_FROM_ABI size_type
[[__nodiscard__]] _LIBCPP_CONSTEXPR_SINCE_CXX14 _LIBCPP_HIDE_FROM_ABI size_type
find_last_of(_CharT __c, size_type __pos = npos) const _NOEXCEPT {
return rfind(__c, __pos);
}
_LIBCPP_CONSTEXPR_SINCE_CXX14 _LIBCPP_HIDE_FROM_ABI size_type
[[__nodiscard__]] _LIBCPP_CONSTEXPR_SINCE_CXX14 _LIBCPP_HIDE_FROM_ABI size_type
find_last_of(const _CharT* __s, size_type __pos, size_type __n) const _NOEXCEPT
_LIBCPP_DIAGNOSE_NULLPTR_IF(__n != 0 && __s == nullptr, " if n is not zero") {
_LIBCPP_ASSERT_NON_NULL(__n == 0 || __s != nullptr, "string_view::find_last_of(): received nullptr");
return std::__str_find_last_of<value_type, size_type, traits_type, npos>(data(), size(), __s, __pos, __n);
}
_LIBCPP_CONSTEXPR_SINCE_CXX14 _LIBCPP_HIDE_FROM_ABI size_type
[[__nodiscard__]] _LIBCPP_CONSTEXPR_SINCE_CXX14 _LIBCPP_HIDE_FROM_ABI size_type
find_last_of(const _CharT* _LIBCPP_DIAGNOSE_NULLPTR __s, size_type __pos = npos) const _NOEXCEPT {
_LIBCPP_ASSERT_NON_NULL(__s != nullptr, "string_view::find_last_of(): received nullptr");
return std::__str_find_last_of<value_type, size_type, traits_type, npos>(
@@ -610,25 +615,25 @@ public:
}
// find_first_not_of
_LIBCPP_CONSTEXPR_SINCE_CXX14 _LIBCPP_HIDE_FROM_ABI size_type
[[__nodiscard__]] _LIBCPP_CONSTEXPR_SINCE_CXX14 _LIBCPP_HIDE_FROM_ABI size_type
find_first_not_of(basic_string_view __s, size_type __pos = 0) const _NOEXCEPT {
return std::__str_find_first_not_of<value_type, size_type, traits_type, npos>(
data(), size(), __s.data(), __pos, __s.size());
}
_LIBCPP_CONSTEXPR_SINCE_CXX14 _LIBCPP_HIDE_FROM_ABI size_type
[[__nodiscard__]] _LIBCPP_CONSTEXPR_SINCE_CXX14 _LIBCPP_HIDE_FROM_ABI size_type
find_first_not_of(_CharT __c, size_type __pos = 0) const _NOEXCEPT {
return std::__str_find_first_not_of<value_type, size_type, traits_type, npos>(data(), size(), __c, __pos);
}
_LIBCPP_CONSTEXPR_SINCE_CXX14 _LIBCPP_HIDE_FROM_ABI size_type
[[__nodiscard__]] _LIBCPP_CONSTEXPR_SINCE_CXX14 _LIBCPP_HIDE_FROM_ABI size_type
find_first_not_of(const _CharT* __s, size_type __pos, size_type __n) const _NOEXCEPT
_LIBCPP_DIAGNOSE_NULLPTR_IF(__n != 0 && __s == nullptr, " if n is not zero") {
_LIBCPP_ASSERT_NON_NULL(__n == 0 || __s != nullptr, "string_view::find_first_not_of(): received nullptr");
return std::__str_find_first_not_of<value_type, size_type, traits_type, npos>(data(), size(), __s, __pos, __n);
}
_LIBCPP_CONSTEXPR_SINCE_CXX14 _LIBCPP_HIDE_FROM_ABI size_type
[[__nodiscard__]] _LIBCPP_CONSTEXPR_SINCE_CXX14 _LIBCPP_HIDE_FROM_ABI size_type
find_first_not_of(const _CharT* _LIBCPP_DIAGNOSE_NULLPTR __s, size_type __pos = 0) const _NOEXCEPT {
_LIBCPP_ASSERT_NON_NULL(__s != nullptr, "string_view::find_first_not_of(): received nullptr");
return std::__str_find_first_not_of<value_type, size_type, traits_type, npos>(
@@ -636,25 +641,25 @@ public:
}
// find_last_not_of
_LIBCPP_CONSTEXPR_SINCE_CXX14 _LIBCPP_HIDE_FROM_ABI size_type
[[__nodiscard__]] _LIBCPP_CONSTEXPR_SINCE_CXX14 _LIBCPP_HIDE_FROM_ABI size_type
find_last_not_of(basic_string_view __s, size_type __pos = npos) const _NOEXCEPT {
return std::__str_find_last_not_of<value_type, size_type, traits_type, npos>(
data(), size(), __s.data(), __pos, __s.size());
}
_LIBCPP_CONSTEXPR_SINCE_CXX14 _LIBCPP_HIDE_FROM_ABI size_type
[[__nodiscard__]] _LIBCPP_CONSTEXPR_SINCE_CXX14 _LIBCPP_HIDE_FROM_ABI size_type
find_last_not_of(_CharT __c, size_type __pos = npos) const _NOEXCEPT {
return std::__str_find_last_not_of<value_type, size_type, traits_type, npos>(data(), size(), __c, __pos);
}
_LIBCPP_CONSTEXPR_SINCE_CXX14 _LIBCPP_HIDE_FROM_ABI size_type
[[__nodiscard__]] _LIBCPP_CONSTEXPR_SINCE_CXX14 _LIBCPP_HIDE_FROM_ABI size_type
find_last_not_of(const _CharT* __s, size_type __pos, size_type __n) const _NOEXCEPT
_LIBCPP_DIAGNOSE_NULLPTR_IF(__n != 0 && __s == nullptr, " if n is not zero") {
_LIBCPP_ASSERT_NON_NULL(__n == 0 || __s != nullptr, "string_view::find_last_not_of(): received nullptr");
return std::__str_find_last_not_of<value_type, size_type, traits_type, npos>(data(), size(), __s, __pos, __n);
}
_LIBCPP_CONSTEXPR_SINCE_CXX14 _LIBCPP_HIDE_FROM_ABI size_type
[[__nodiscard__]] _LIBCPP_CONSTEXPR_SINCE_CXX14 _LIBCPP_HIDE_FROM_ABI size_type
find_last_not_of(const _CharT* _LIBCPP_DIAGNOSE_NULLPTR __s, size_type __pos = npos) const _NOEXCEPT {
_LIBCPP_ASSERT_NON_NULL(__s != nullptr, "string_view::find_last_not_of(): received nullptr");
return std::__str_find_last_not_of<value_type, size_type, traits_type, npos>(
@@ -662,37 +667,43 @@ public:
}
# if _LIBCPP_STD_VER >= 20
constexpr _LIBCPP_HIDE_FROM_ABI bool starts_with(basic_string_view __s) const noexcept {
[[nodiscard]] constexpr _LIBCPP_HIDE_FROM_ABI bool starts_with(basic_string_view __s) const noexcept {
return size() >= __s.size() && compare(0, __s.size(), __s) == 0;
}
constexpr _LIBCPP_HIDE_FROM_ABI bool starts_with(value_type __c) const noexcept {
[[nodiscard]] constexpr _LIBCPP_HIDE_FROM_ABI bool starts_with(value_type __c) const noexcept {
return !empty() && _Traits::eq(front(), __c);
}
constexpr _LIBCPP_HIDE_FROM_ABI bool starts_with(const value_type* _LIBCPP_DIAGNOSE_NULLPTR __s) const noexcept {
[[nodiscard]] constexpr _LIBCPP_HIDE_FROM_ABI bool
starts_with(const value_type* _LIBCPP_DIAGNOSE_NULLPTR __s) const noexcept {
return starts_with(basic_string_view(__s));
}
constexpr _LIBCPP_HIDE_FROM_ABI bool ends_with(basic_string_view __s) const noexcept {
[[nodiscard]] constexpr _LIBCPP_HIDE_FROM_ABI bool ends_with(basic_string_view __s) const noexcept {
return size() >= __s.size() && compare(size() - __s.size(), npos, __s) == 0;
}
constexpr _LIBCPP_HIDE_FROM_ABI bool ends_with(value_type __c) const noexcept {
[[nodiscard]] constexpr _LIBCPP_HIDE_FROM_ABI bool ends_with(value_type __c) const noexcept {
return !empty() && _Traits::eq(back(), __c);
}
constexpr _LIBCPP_HIDE_FROM_ABI bool ends_with(const value_type* _LIBCPP_DIAGNOSE_NULLPTR __s) const noexcept {
[[nodiscard]] constexpr _LIBCPP_HIDE_FROM_ABI bool
ends_with(const value_type* _LIBCPP_DIAGNOSE_NULLPTR __s) const noexcept {
return ends_with(basic_string_view(__s));
}
# endif
# if _LIBCPP_STD_VER >= 23
constexpr _LIBCPP_HIDE_FROM_ABI bool contains(basic_string_view __sv) const noexcept { return find(__sv) != npos; }
[[nodiscard]] constexpr _LIBCPP_HIDE_FROM_ABI bool contains(basic_string_view __sv) const noexcept {
return find(__sv) != npos;
}
constexpr _LIBCPP_HIDE_FROM_ABI bool contains(value_type __c) const noexcept { return find(__c) != npos; }
[[nodiscard]] constexpr _LIBCPP_HIDE_FROM_ABI bool contains(value_type __c) const noexcept {
return find(__c) != npos;
}
constexpr _LIBCPP_HIDE_FROM_ABI bool contains(const value_type* _LIBCPP_DIAGNOSE_NULLPTR __s) const {
[[nodiscard]] constexpr _LIBCPP_HIDE_FROM_ABI bool contains(const value_type* _LIBCPP_DIAGNOSE_NULLPTR __s) const {
return find(__s) != npos;
}
# endif
@@ -897,7 +908,8 @@ operator<<(basic_ostream<_CharT, _Traits>& __os, basic_string_view<_CharT, _Trai
// [string.view.hash]
template <class _CharT>
struct __string_view_hash : public __unary_function<basic_string_view<_CharT, char_traits<_CharT> >, size_t> {
_LIBCPP_HIDE_FROM_ABI size_t operator()(const basic_string_view<_CharT, char_traits<_CharT> > __val) const _NOEXCEPT {
[[__nodiscard__]] _LIBCPP_HIDE_FROM_ABI size_t
operator()(const basic_string_view<_CharT, char_traits<_CharT> > __val) const _NOEXCEPT {
return std::__do_string_hash(__val.data(), __val.data() + __val.size());
}
};
@@ -924,30 +936,31 @@ struct hash<basic_string_view<wchar_t, char_traits<wchar_t> > > : __string_view_
# if _LIBCPP_STD_VER >= 14
inline namespace literals {
inline namespace string_view_literals {
inline _LIBCPP_HIDE_FROM_ABI constexpr basic_string_view<char> operator""sv(const char* __str, size_t __len) noexcept {
[[__nodiscard__]] inline _LIBCPP_HIDE_FROM_ABI constexpr basic_string_view<char>
operator""sv(const char* __str, size_t __len) noexcept {
return basic_string_view<char>(__str, __len);
}
# if _LIBCPP_HAS_WIDE_CHARACTERS
inline _LIBCPP_HIDE_FROM_ABI constexpr basic_string_view<wchar_t>
[[__nodiscard__]] inline _LIBCPP_HIDE_FROM_ABI constexpr basic_string_view<wchar_t>
operator""sv(const wchar_t* __str, size_t __len) noexcept {
return basic_string_view<wchar_t>(__str, __len);
}
# endif
# if _LIBCPP_HAS_CHAR8_T
inline _LIBCPP_HIDE_FROM_ABI constexpr basic_string_view<char8_t>
[[nodiscard]] inline _LIBCPP_HIDE_FROM_ABI constexpr basic_string_view<char8_t>
operator""sv(const char8_t* __str, size_t __len) noexcept {
return basic_string_view<char8_t>(__str, __len);
}
# endif
inline _LIBCPP_HIDE_FROM_ABI constexpr basic_string_view<char16_t>
[[__nodiscard__]] inline _LIBCPP_HIDE_FROM_ABI constexpr basic_string_view<char16_t>
operator""sv(const char16_t* __str, size_t __len) noexcept {
return basic_string_view<char16_t>(__str, __len);
}
inline _LIBCPP_HIDE_FROM_ABI constexpr basic_string_view<char32_t>
[[__nodiscard__]] inline _LIBCPP_HIDE_FROM_ABI constexpr basic_string_view<char32_t>
operator""sv(const char32_t* __str, size_t __len) noexcept {
return basic_string_view<char32_t>(__str, __len);
}

View File

@@ -12,12 +12,140 @@
#include <string_view>
#include "type_algorithms.h"
#include "test_macros.h"
void test() {
std::string_view string_view;
string_view.empty(); // expected-warning {{ignoring return value of function declared with 'nodiscard' attribute}}
void test_members() {
std::string_view sv;
sv.begin(); // expected-warning {{ignoring return value of function declared with 'nodiscard' attribute}}
sv.end(); // expected-warning {{ignoring return value of function declared with 'nodiscard' attribute}}
sv.cbegin(); // expected-warning {{ignoring return value of function declared with 'nodiscard' attribute}}
sv.cend(); // expected-warning {{ignoring return value of function declared with 'nodiscard' attribute}}
sv.rbegin(); // expected-warning {{ignoring return value of function declared with 'nodiscard' attribute}}
sv.rend(); // expected-warning {{ignoring return value of function declared with 'nodiscard' attribute}}
sv.crbegin(); // expected-warning {{ignoring return value of function declared with 'nodiscard' attribute}}
sv.crend(); // expected-warning {{ignoring return value of function declared with 'nodiscard' attribute}}
sv.size(); // expected-warning {{ignoring return value of function declared with 'nodiscard' attribute}}
sv.length(); // expected-warning {{ignoring return value of function declared with 'nodiscard' attribute}}
sv.max_size(); // expected-warning {{ignoring return value of function declared with 'nodiscard' attribute}}
sv.empty(); // expected-warning {{ignoring return value of function declared with 'nodiscard' attribute}}
sv[0]; // expected-warning {{ignoring return value of function declared with 'nodiscard' attribute}}
sv.at(0); // expected-warning {{ignoring return value of function declared with 'nodiscard' attribute}}
sv.front(); // expected-warning {{ignoring return value of function declared with 'nodiscard' attribute}}
sv.back(); // expected-warning {{ignoring return value of function declared with 'nodiscard' attribute}}
sv.data(); // expected-warning {{ignoring return value of function declared with 'nodiscard' attribute}}
sv.substr(); // expected-warning {{ignoring return value of function declared with 'nodiscard' attribute}}
#if TEST_STD_VER >= 26
string_view.subview(); // expected-warning {{ignoring return value of function declared with 'nodiscard' attribute}}
sv.subview(); // expected-warning {{ignoring return value of function declared with 'nodiscard' attribute}}
#endif
// expected-warning@+1 {{ignoring return value of function declared with 'nodiscard' attribute}}
sv.compare(sv);
// expected-warning@+1 {{ignoring return value of function declared with 'nodiscard' attribute}}
sv.compare(0, 0, sv);
// expected-warning@+1 {{ignoring return value of function declared with 'nodiscard' attribute}}
sv.compare(0, 0, sv, 0, 0);
// expected-warning@+1 {{ignoring return value of function declared with 'nodiscard' attribute}}
sv.compare("");
// expected-warning@+1 {{ignoring return value of function declared with 'nodiscard' attribute}}
sv.compare(0, 0, "");
// expected-warning@+1 {{ignoring return value of function declared with 'nodiscard' attribute}}
sv.compare(0, 0, "", 0);
sv.find(sv); // expected-warning {{ignoring return value of function declared with 'nodiscard' attribute}}
sv.find(' '); // expected-warning {{ignoring return value of function declared with 'nodiscard' attribute}}
sv.find("", 0, 0); // expected-warning {{ignoring return value of function declared with 'nodiscard' attribute}}
sv.find("", 0); // expected-warning {{ignoring return value of function declared with 'nodiscard' attribute}}
sv.rfind(sv); // expected-warning {{ignoring return value of function declared with 'nodiscard' attribute}}
sv.rfind(' '); // expected-warning {{ignoring return value of function declared with 'nodiscard' attribute}}
sv.rfind("", 0, 0); // expected-warning {{ignoring return value of function declared with 'nodiscard' attribute}}
sv.rfind("", 0); // expected-warning {{ignoring return value of function declared with 'nodiscard' attribute}}
// expected-warning@+1 {{ignoring return value of function declared with 'nodiscard' attribute}}
sv.find_first_of(sv);
// expected-warning@+1 {{ignoring return value of function declared with 'nodiscard' attribute}}
sv.find_first_of(' ');
// expected-warning@+1 {{ignoring return value of function declared with 'nodiscard' attribute}}
sv.find_first_of("", 0, 0);
// expected-warning@+1 {{ignoring return value of function declared with 'nodiscard' attribute}}
sv.find_first_of("", 0);
// expected-warning@+1 {{ignoring return value of function declared with 'nodiscard' attribute}}
sv.find_last_of(sv);
// expected-warning@+1 {{ignoring return value of function declared with 'nodiscard' attribute}}
sv.find_last_of(' ');
// expected-warning@+1 {{ignoring return value of function declared with 'nodiscard' attribute}}
sv.find_last_of("", 0, 0);
// expected-warning@+1 {{ignoring return value of function declared with 'nodiscard' attribute}}
sv.find_last_of("", 0);
// expected-warning@+1 {{ignoring return value of function declared with 'nodiscard' attribute}}
sv.find_first_not_of(sv);
// expected-warning@+1 {{ignoring return value of function declared with 'nodiscard' attribute}}
sv.find_first_not_of(' ');
// expected-warning@+1 {{ignoring return value of function declared with 'nodiscard' attribute}}
sv.find_first_not_of("", 0, 0);
// expected-warning@+1 {{ignoring return value of function declared with 'nodiscard' attribute}}
sv.find_first_not_of("", 0);
// expected-warning@+1 {{ignoring return value of function declared with 'nodiscard' attribute}}
sv.find_last_not_of(sv);
// expected-warning@+1 {{ignoring return value of function declared with 'nodiscard' attribute}}
sv.find_last_not_of(' ');
// expected-warning@+1 {{ignoring return value of function declared with 'nodiscard' attribute}}
sv.find_last_not_of("", 0, 0);
// expected-warning@+1 {{ignoring return value of function declared with 'nodiscard' attribute}}
sv.find_last_not_of("", 0);
#if TEST_STD_VER >= 20
sv.starts_with(sv); // expected-warning {{ignoring return value of function declared with 'nodiscard' attribute}}
sv.starts_with(' '); // expected-warning {{ignoring return value of function declared with 'nodiscard' attribute}}
sv.starts_with(""); // expected-warning {{ignoring return value of function declared with 'nodiscard' attribute}}
sv.ends_with(sv); // expected-warning {{ignoring return value of function declared with 'nodiscard' attribute}}
sv.ends_with(' '); // expected-warning {{ignoring return value of function declared with 'nodiscard' attribute}}
sv.ends_with(""); // expected-warning {{ignoring return value of function declared with 'nodiscard' attribute}}
#endif
#if TEST_STD_VER >= 23
sv.contains(sv); // expected-warning {{ignoring return value of function declared with 'nodiscard' attribute}}
sv.contains(' '); // expected-warning {{ignoring return value of function declared with 'nodiscard' attribute}}
sv.contains(""); // expected-warning {{ignoring return value of function declared with 'nodiscard' attribute}}
#endif
}
void test_nonmembers() {
// std::hash<>
std::hash<std::string_view> hash;
// expected-warning@+1 {{ignoring return value of function declared with 'nodiscard' attribute}}
hash(std::string_view{});
#if TEST_STD_VER >= 14
// string_view literals
using namespace std::string_view_literals;
// expected-warning@+1 {{ignoring return value of function declared with 'nodiscard' attribute}}
""sv; // const char*
# if !defined(TEST_HAS_NO_WIDE_CHARACTERS)
// expected-warning@+1 {{ignoring return value of function declared with 'nodiscard' attribute}}
L""sv; // const wchar_t*
# endif
# if !defined(TEST_HAS_NO_CHAR8_T)
// expected-warning@+1 {{ignoring return value of function declared with 'nodiscard' attribute}}
u8""sv; // const char8_t*
# endif
// expected-warning@+1 {{ignoring return value of function declared with 'nodiscard' attribute}}
u""sv; // const char16_t*
// expected-warning@+1 {{ignoring return value of function declared with 'nodiscard' attribute}}
U""sv; // const char32_t*
#endif
}

View File

@@ -10,8 +10,10 @@
// Ensure that APIs which take a CharT* are diagnosing passing a nullptr to them
// Clang 19 and AppleClang don't have diagnose_if with diagnostic flags
// UNSUPPORTED: clang-19, apple-clang-17
// AppleClang doesn't have diagnose_if with diagnostic flags
// UNSUPPORTED: apple-clang-17
// ADDITIONAL_COMPILE_FLAGS: -Wno-unused-result
#include <string_view>