Skip to content

src: restrict MaybeStackBuffer string helpers to text types #62564

New issue

Have a question about this project? Sign up for a free GitHub account to open an issue and contact its maintainers and the community.

Sign up for GitHub

By clicking “Sign up for GitHub”, you agree to our terms of service and privacy statement. We’ll occasionally send you account related emails.

Already on GitHub? Sign in to your account

Closed
anonrig wants to merge 1 commit into from
+32 −3
Closed

src: restrict MaybeStackBuffer string helpers to text types #62564

Changes from all commits
Commits
Show all changes
1 commit
Select commit
File filter

Filter by extension

Filter by extension
Conversations
Failed to load comments.
Loading
Jump to
Jump to file
Failed to load files.
Loading
Diff view
Diff view
35 changes: 32 additions & 3 deletions src/util.h
View file
Open in desktop
Original file line number Diff line number Diff line change
Expand Up @@ -390,6 +390,16 @@ constexpr size_t strsize(const T (&)[N]) {
return N - 1;
}

template <typename T>
inline constexpr bool kMaybeStackBufferHasStringType =
std::is_same_v<T, char> || std::is_same_v<T, wchar_t> ||
std::is_same_v<T, char8_t> || std::is_same_v<T, char16_t> ||
std::is_same_v<T, char32_t> || std::is_same_v<T, uint16_t>;

template <typename T>
using MaybeStackBufferStringType =
std::conditional_t<std::is_same_v<T, uint16_t>, char16_t, T>;
Copy link
Copy Markdown
Member

@jasnell jasnell Apr 2, 2026

Choose a reason for hiding this comment

The reason will be displayed to describe this comment to others. Learn more.

This should just be a concept

   template <typename T>
  concept MaybeStackBufferStringLike =
      std::is_same_v<T, char> || std::is_same_v<T, wchar_t> ||
      std::is_same_v<T, char8_t> || std::is_same_v<T, char16_t> ||
      std::is_same_v<T, char32_t> || std::is_same_v<T, uint16_t>;

// ...

template <MaybeStackBufferStringLike U = T,
        typename Char = MaybeStackBufferStringType<U>>


// Allocates an array of member type T. For up to kStackStorageSize items,
// the stack is used, otherwise malloc().
template <typename T, size_t kStackStorageSize = 1024>
Expand Down Expand Up @@ -503,9 +513,28 @@ class MaybeStackBuffer {
free(buf_);
}

inline std::basic_string<T> ToString() const { return {out(), length()}; }
inline std::basic_string_view<T> ToStringView() const {
return {out(), length()};
// Restrict string helpers to textual element types. libc++ deprecates
// `char_traits<T>` for byte-oriented types like `unsigned char`.
template <typename U = T,
typename Char = MaybeStackBufferStringType<U>>
requires(kMaybeStackBufferHasStringType<U>)
inline std::basic_string<Char> ToString() const {
if constexpr (std::is_same_v<U, Char>) {
return {out(), length()};
} else {
return {reinterpret_cast<const Char*>(out()), length()};
}
}

template <typename U = T,
typename Char = MaybeStackBufferStringType<U>>
requires(kMaybeStackBufferHasStringType<U>)
inline std::basic_string_view<Char> ToStringView() const {
if constexpr (std::is_same_v<U, Char>) {
return {out(), length()};
} else {
return {reinterpret_cast<const Char*>(out()), length()};
}
}
// This can only be used if the buffer contains path data in UTF8
inline std::filesystem::path ToPath() const;
Expand Down
Loading