Fixed-width string types for Julia
Author JuliaStrings
35 Stars
Updated Last
9 Months Ago
Started In
September 2021


CI codecov deps version pkgeval

Fixed-width string types for facilitating certain string workflows in Julia


The package is registered in the General registry and so can be installed with Pkg.add.

julia> using Pkg; Pkg.add("InlineStrings")

Project Status

The package is tested against the latest Julia 1.x release, the long-term support release 1.6, and nightly on Linux, OS X, and Windows.

Contributing and Questions

Contributions are very welcome, as are feature requests and suggestions. Please open an issue if you encounter any problems or would just like to ask a question.



A set of custom string types of various fixed sizes. Each inline string is a custom primitive type and can benefit from being stack friendly by avoiding allocations/heap tracking in the GC. When used in an array, the elements are able to be stored inline since each one has a fixed size. Currently support inline strings from 1 byte up to 255 bytes.

The following types are supported: String1, String3, String7, String15, String31, String63, String127, String255.

InlineStrings can be constructed by passing an AbstractString, byte vector (AbstractVector{UInt8}) and position and length, or a pointer (Ptr{UInt8}) and length. See the docstring for any individual InlineString type for more details (like ?String3).

To generically turn any string into the smallest possible InlineString type, call InlineString(x). To convert any iterator/array of strings to a single, promoted InlineString type, the inlinestrings(A) utility function is exported.