Struct StrVecBuilder 

pub struct StrVecBuilder<'a> {
    vec: SEXP,
    _scope: &'a ProtectScope,
}

Builder for constructing string vectors with efficient protection management.

Example

unsafe fn build_strvec(strings: &[&str]) -> SEXP {
    let scope = ProtectScope::new();
    let builder = StrVecBuilder::new(&scope, strings.len() as isize);

    for (i, s) in strings.iter().enumerate() {
        builder.set_str(i as isize, s);
    }

    builder.into_sexp()
}

Fields

vec: SEXP

_scope: &'a ProtectScope

Implementations

impl<'a> StrVecBuilder<'a>

pub unsafe fn new(scope: &'a ProtectScope, len: usize) -> Self

Create a new string vector builder with the given length.

Safety

Must be called from the R main thread.

pub unsafe fn new_unchecked(scope: &'a ProtectScope, len: usize) -> Self

Create a new string vector builder via the unchecked FFI allocation path.

_unchecked twin of new: the STRSXP is allocated with Rf_allocVector_unchecked (see ProtectScope::alloc_character_unchecked), bypassing the main-thread assertion. Use inside ALTREP callbacks, with_r_unwind_protect, or with_r_thread bodies, and pair element insertion with the _unchecked string-element setters.

Safety

Must be called from the R main thread, in a context where the checked-FFI assertion is intentionally bypassed (see CLAUDE.md “FFI thread checking”).

pub unsafe fn set_str(&self, idx: isize, s: &str)

Set an element from a Rust string.

Safety

Must be called from the R main thread.

pub unsafe fn set_na(&self, idx: isize)

Set an element to NA_character_.

Safety

Must be called from the R main thread.

pub unsafe fn set_opt_str(&self, idx: isize, s: Option<&str>)

Set an element from an optional string.

Safety

Must be called from the R main thread.

pub fn as_sexp(&self) -> SEXP

Get the underlying SEXP.

pub fn into_strvec(self) -> StrVec<'a>

Convert to a StrVec view, leashed to the builder’s protect scope 'a.

pub fn into_sexp(self) -> SEXP

Convert to the underlying SEXP.

pub fn len(&self) -> isize

Get the length.

pub fn is_empty(&self) -> bool

Check if empty.

Layout

Note: Most layout information is completely unstable and may even differ between compilations. The only exception is types with certain repr(...) attributes. Please see the Rust Reference's “Type Layout” chapter for details on type layout guarantees.

Size: 16 bytes