Feature alloc for graphics

Cargo.toml

@@ -28,3 +28,10 @@ x86_64 = "0.9.6"
 [dependencies.num-traits]
 version = "0.2.11"
 default-features = false
+
+[features]
+default = []
+alloc = []
+
+[package.metadata.docs.rs]
+features = ["alloc"]

src/lib.rs

@@ -7,6 +7,7 @@
 #![no_std]
 #![warn(missing_docs)]
 
+#[cfg(feature = "alloc")]
 extern crate alloc;
 
 pub mod colors;

src/writers/mod.rs

@@ -1,5 +1,7 @@
 //! Writers for common vga modes.
+#[cfg(feature = "alloc")]
 mod graphics_320x200x256;
+#[cfg(feature = "alloc")]
 mod graphics_640x480x16;
 mod text_40x25;
 mod text_40x50;
@@ -11,7 +13,9 @@ use super::{
     vga::VGA,
 };
 
+#[cfg(feature = "alloc")]
 pub use graphics_320x200x256::Graphics320x200x256;
+#[cfg(feature = "alloc")]
 pub use graphics_640x480x16::Graphics640x480x16;
 pub use text_40x25::Text40x25;
 pub use text_40x50::Text40x50;