Function CGContextBeginTransparencyLayerWithRect 

pub unsafe extern "C-unwind" fn CGContextBeginTransparencyLayerWithRect(
    c: Option<&CGContext>,
    rect: CGRect,
    aux_info: Option<&CFDictionary>,
)

👎Deprecated: renamed to CGContext::begin_transparency_layer_with_rect

Available on crate feature CGContext only.