import type { EntityHandle as SchemaEntityHandle, EntityIndex as SchemaEntityIndex } from '@ecsia/schema';
/** A packed u32: [generation: generationBits][index: indexBits], generation in the HIGH bits. */
export type EntityHandle = SchemaEntityHandle;
/** The low-bits index portion — the slot in the dense/sparse arrays. */
export type EntityIndex = SchemaEntityIndex;
/** The generation (version) counter for a slot. */
export type EntityGeneration = number & {
    readonly __ecsiaEntityGeneration: unique symbol;
};
export interface HandleLayout {
    readonly indexBits: number;
    readonly generationBits: number;
    /** Low-bits mask isolating the index. */
    readonly indexMask: number;
    /** Unshifted generation mask (`(1 << generationBits) - 1`). */
    readonly generationMask: number;
    /** `=== indexBits`. */
    readonly generationShift: number;
    /** Largest valid index (`indexMask`). */
    readonly maxIndex: number;
    /** Generation value just before wrap to 0 (`generationMask`). */
    readonly maxGeneration: number;
    /** Number of addressable slots (`maxIndex + 1`). */
    readonly capacity: number;
}
/** Sentinel for "no entity" in eid fields and APIs that may return absent. NOT a live handle. */
export declare const NO_ENTITY: EntityHandle;
/** Alias of {@link NO_ENTITY} for call sites that prefer the "null handle" spelling. */
export declare const NULL_ENTITY: SchemaEntityHandle;
/**
 * True when `handle` is the {@link NO_ENTITY} sentinel (an absent / null handle). Use this to
 * discriminate handles returned from APIs that may yield "no entity" without comparing against the
 * raw `0xffffffff` literal: `if (isNoEntity(h)) { ... }`.
 */
export declare function isNoEntity(handle: EntityHandle): boolean;
/**
 * Build the immutable handle layout from a generation-bit split. `indexBits = 32 -
 * generationBits`. `1 << 32` is 1 in JS (shift is mod-32), so the all-ones index mask is
 * special-cased for `generationBits === 0`.
 */
export declare function makeHandleLayout(generationBits: number): HandleLayout;
export declare function makeHandle(index: number, generation: number, layout: HandleLayout): EntityHandle;
export declare function handleIndex(handle: EntityHandle, layout: HandleLayout): EntityIndex;
export declare function handleGeneration(handle: EntityHandle, layout: HandleLayout): EntityGeneration;
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