/**
 * Util for converting a css pixel size value to a number (of pixels).
 *
 * ie.
 * ```ts
 * const pixels = parsePx('10px')
 * //    ^$ const pixels: number
 * ```
 * * ```ts
 * const pixels = parsePx('10')
 * //    ^$ const pixels: number | undefined
 * ```
 */
export declare function parsePx<PXString extends `${number}px`>(pxStr: PXString): number;
export declare function parsePx<PXString extends string>(pxStr: PXString): number | undefined;