Struct EnumTableBuilder

Source

pub struct EnumTableBuilder<K: Enumable, V, const N: usize> { /* private fields */ }

Expand description

A builder for creating an EnumTable with a specified number of elements.

EnumTableBuilder allows for the incremental construction of an EnumTable by pushing elements one by one and then building the final table.

§Note

The builder is expected to be filled completely before building the table. If the builder is not filled completely, the build and build_to method will panic. For a clearer and more concise approach, consider using the crate::et macro.

§Example

use enum_table::{EnumTable, Enumable, builder::EnumTableBuilder,};

#[derive(Debug, Copy, Clone, Enumable)]
enum Test {
    A,
    B,
    C,
}

const TABLE: EnumTable<Test, &'static str, { Test::COUNT }> = {
   let mut builder = EnumTableBuilder::<Test, &'static str, { Test::COUNT }>::new();
   unsafe {
       builder.push_unchecked(&Test::A, "A");
       builder.push_unchecked(&Test::B, "B");
       builder.push_unchecked(&Test::C, "C");
       builder.build_to_unchecked()
   }
};

// Access values associated with enum variants
assert_eq!(TABLE.get(&Test::A), &"A");
assert_eq!(TABLE.get(&Test::B), &"B");
assert_eq!(TABLE.get(&Test::C), &"C");

Implementations§

Source §

impl<K: Enumable, V, const N: usize> EnumTableBuilder<K, V, N>

Source

pub const fn new() -> Self

Creates a new EnumTableBuilder with an uninitialized table.

§Returns

A new instance of EnumTableBuilder.

Source

pub const unsafe fn push_unchecked(&mut self, variant: &K, value: V)

Pushes a new element into the builder without safety checks.

§Safety

The caller must ensure that elements are pushed in the correct order (sorted by discriminant).
The caller must ensure that no variant is pushed more than once.
The caller must ensure that the builder doesn’t exceed capacity N.

§Arguments

variant - A reference to an enumeration variant.
value - The value to associate with the variant.

Source

pub const unsafe fn build_unchecked(self) -> [(usize, V); N]

Builds the table from the pushed elements without checking if all variants are filled.

§Safety

The caller must ensure that all N variants have been pushed to the builder. If this is not the case, the resulting table will contain uninitialized memory.