API Reference — status/Provider

ArgIndices

A local alias, inside StatusProvider::set, for the MakeISeq sequence covering the variadic arguments' positions.

Why this exists

ArgIndices names the specific index sequence — impl::MakeISeq<sizeof...(Args), 1> — used to number each variadic argument to set starting at position 1, so it can be passed into the ISeq-based overload of set in one readable expression.

Relationships

  • MakeISeq — the alias this local type resolves through.
  • StatusProvider — the class whose set method defines and uses this alias.

impl::ISeq

A compile-time sequence of std::size_t indices, used internally to unpack variadic argument positions.

Why this exists

StatusProvider::set needs to pass each variadic argument through a per-argument hook (execHook) along with its 1-based position. ISeq (built by Make/MakeISeq) generates that index sequence at compile time so the position can be threaded through without runtime overhead or manual unpacking.

Relationships

  • Make / MakeISeq — the metafunctions that construct an ISeq of a given size and offset.
  • StatusProvider — the class whose variadic set overload consumes an ISeq.

impl::Make

A compile-time recursive template that builds an ISeq of a given size, starting at a given offset.

Why this exists

Generating an index sequence like {1, 2, 3} for a fixed argument count needs to happen without runtime cost. Make recursively peels one index off the requested size until it reaches the Make<0, Offset, Is...> base case, which captures the accumulated indices as an ISeq.

Relationships

  • ISeq — the type ultimately produced by Make's recursion.
  • MakeISeq — the convenience alias that exposes Make<Size, Offset>::Type directly.

impl::MakeISeq

A convenience alias for Make<Size, Offset>::Type, producing an ISeq of Size indices starting at Offset.

Why this exists

Using Make<Size, Offset>::Type directly at every call site is verbose. MakeISeq hides the recursive Make machinery behind a single alias, and defaults Offset to 0 for the common case.

Relationships

  • Make — the recursive template this alias resolves through.
  • StatusProvider — uses impl::MakeISeq<sizeof...(Args), 1> to number variadic arguments starting at 1.

class SCAPI StatusProvider

Formats and records status messages with printf-style interpolation, running each argument through an optional hook before formatting.

When to use this

Use StatusProvider::set when raising a status/error that needs formatted, interpolated arguments (e.g. a file path or resource name) instead of a fixed message string. Use StatusProvider::get/isOk to check the current status after calling code that reports through this mechanism.

Method groups

Group Methods
Lifecycle StatusProvider (constructor)
Query reset, get, isOk
Reporting set

Example

sc::StatusProvider provider{StatusCode{1, "Failed to open file: %s"}};
sc::StatusProvider::set(StatusCode{1, "Failed to open file: %s"}, "rig.dna");
if (!sc::StatusProvider::isOk()) {
    // handle the formatted status message
}

Parameters

Name Type Description
statuses std::initializer_list<StatusCode> The set of status codes this provider is responsible for registering.
status StatusCode required (on set). The status code/message template to report.
args Args&&... optional (on set). Values interpolated into the status message via snprintf, each passed through execHook first.

Watch out for

  • The variadic set(StatusCode, Args&&...) overload builds an ISeq starting at index 1 (not 0) — index 0 is reserved for hooking the message template itself.
  • Formatted messages are truncated to a fixed 512-byte buffer (bufferSize); very long interpolated arguments can be cut off.
  • -Wformat-security is deliberately suppressed around the snprintf calls because the format string comes from status.message, not a literal — callers must ensure status.message's format specifiers match the arguments passed.
  • The formatted message buffer is fixed at 512 bytes. Strings longer than 511 characters are silently truncated by snprintf.
  • execHook is called once for the message string itself (index 0) and once per const char* argument (indices 1…N). Hook return values override the originals. Arguments of any other type bypass the hook entirely.
  • reset(), get(), isOk(), and set() are all static — they operate on shared (per-TU or global) state. Concurrent calls without external synchronisation are unsafe.