Bytes4Builder

Asset Tokenization Studio Team

Bytes4Builder

Library of overloaded build helpers that allocate and populate a bytes4[] memory array of fixed length, intended for use by IStaticFunctionSelectors implementations when reporting selectors or interface ids to the resolver.

Solidity does not allow [a, b, c] (a fixed-size bytesN[N] memory literal) to be implicitly returned as a dynamic bytes4[] memory; these internal pure overloads provide the missing one-liner construction without the descending --selectorIndex boilerplate that facets otherwise carry. The compiler inlines each call, so the only runtime cost is argument marshalling onto the stack. Overloads are provided for 1 through 12 elements. Facets needing larger arrays should fall back to the manual descending-loop form rather than padding this library with ever-wider overloads — the readability win flattens once N grows past the cap.