Skip to content

[Support] Use a C++17 fold expression in a static_assert (NFC) #161479

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

Merged
merged 1 commit into from
Oct 1, 2025
+3 −11
Merged

[Support] Use a C++17 fold expression in a static_assert (NFC) #161479

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
14 changes: 3 additions & 11 deletions llvm/include/llvm/Support/Format.h
View file
Open in desktop
Original file line number Diff line number Diff line change
Expand Up @@ -78,16 +78,6 @@ class LLVM_ABI format_object_base {
/// printed, this synthesizes the string into a temporary buffer provided and
/// returns whether or not it is big enough.

// Helper to validate that format() parameters are scalars or pointers.
template <typename... Args> struct validate_format_parameters;
template <typename Arg, typename... Args>
struct validate_format_parameters<Arg, Args...> {
static_assert(std::is_scalar_v<Arg>,
"format can't be used with non fundamental / non pointer type");
validate_format_parameters() { validate_format_parameters<Args...>(); }
};
template <> struct validate_format_parameters<> {};

template <typename... Ts>
class format_object final : public format_object_base {
std::tuple<Ts...> Vals;
Expand All @@ -105,7 +95,9 @@ class format_object final : public format_object_base {
public:
format_object(const char *fmt, const Ts &... vals)
: format_object_base(fmt), Vals(vals...) {
validate_format_parameters<Ts...>();
static_assert(
(std::is_scalar_v<Ts> && ...),
"format can't be used with non fundamental / non pointer type");
}

int snprint(char *Buffer, unsigned BufferSize) const override {
Expand Down