/**
 * Coerces a string or numeric value into a valid CSS size length value (width, height, etc.)
 * If the value is numeric it will assume that is expressed in pixels
 * @param value - the value to coerce.
 *
 * @internal
 *
 */
export declare function coerceSizeValue(value?: string | number): string | undefined;
/**
 * Coerces a string or numeric size value to a pixel number.
 * Returns `undefined` when the value is a non-pixel string (e.g. `'100%'`, `'vh'`, `'rem'`).
 *
 * @internal
 */
export declare function coerceSizeValueToPixels(value: number | string | undefined): number | undefined;