Enum ruby_rstring_flags 

#[repr(u32)]
pub enum ruby_rstring_flags {
    RSTRING_NOEMBED = 8_192,
    RSTRING_FSTR = 536_870_912,
}

---

Private

Bits that you can set to ::RBasic::flags.

@warning These enums are not the only bits we use for strings.

@internal

Actually all bits through FL_USER1 to FL_USER19 are used for strings. Why only this tiny part of them are made public here? @shyouhei can find no reason.

Generated by rb-sys for Ruby mri-x86_64-linux-gnu-3.2.3

Variants

RSTRING_NOEMBED = 8_192

This flag has something to do with memory footprint. If the string is short enough, ruby tries to be creative to abuse padding bits of struct ::RString for storing contents. If this flag is set that string does not do that, to resort to good old fashioned external allocation strategy instead.

@warning This bit has to be considered read-only. Setting/clearing this bit without corresponding fix up must cause immediate SEGV. Also, internal structures of a string change dynamically and transparently throughout of its lifetime. Don’t assume it being persistent.

@internal

3rd parties must not be aware that there even is more than one way to store a string. Might better be hidden.

Generated by rb-sys for Ruby mri-x86_64-linux-gnu-3.2.3

RSTRING_FSTR = 536_870_912

This flag has something to do with infamous “f“string. What is a fstring? Well it is a special subkind of strings that is immutable, deduped globally, and managed by our GC. It is much like a Symbol (in fact Symbols are dynamic these days and are backended using fstrings). This concept has been silently introduced at some point in 2.x era. Since then it gained wider acceptance in the core. But extension libraries could not know that until very recently. Strings of this flag live in a special Limbo deep inside of the interpreter. Never try to manipulate it by hand.

@internal

Fstrings are not the only variant strings that we implement today. Other things are behind-the-scene. This is the only one that is visible from extension library. There is no clear reason why it has to be. Given there are more “polite” ways to create fstrings, it seems this bit need not be exposed to extension libraries. Might better be hidden.

Generated by rb-sys for Ruby mri-x86_64-linux-gnu-3.2.3

Trait Implementations

impl Clone for ruby_rstring_flags

fn clone(&self) -> ruby_rstring_flags

Returns a duplicate of the value.

fn clone_from(&mut self, source: &Self)

Performs copy-assignment from source.

impl Debug for ruby_rstring_flags

fn fmt(&self, f: &mut Formatter<'_>) -> Result

Formats the value using the given formatter.

impl Hash for ruby_rstring_flags

fn hash<__H: Hasher>(&self, state: &mut __H)

Feeds this value into the given Hasher.

fn hash_slice<H>(data: &[Self], state: &mut H)

where H: Hasher, Self: Sized,

Feeds a slice of this type into the given Hasher.

impl PartialEq for ruby_rstring_flags

fn eq(&self, other: &ruby_rstring_flags) -> bool

Tests for self and other values to be equal, and is used by ==.

fn ne(&self, other: &Rhs) -> bool

Tests for !=. The default implementation is almost always sufficient, and should not be overridden without very good reason.

impl Copy for ruby_rstring_flags

impl Eq for ruby_rstring_flags

impl StructuralPartialEq for ruby_rstring_flags