[examples/Subpeep] Use pdsl_core::memory utilities instead of alloc

examples/subpeep/src/lib.rs

-#![feature(alloc_error_handler)]
-#![feature(core_intrinsics)]
-#![feature(alloc)]
-
 #![no_std]
 
 #[cfg(all(test, feature = "test-env"))]
 mod tests;
 mod utils;
 
-#[cfg_attr(test, macro_use)]
-extern crate alloc;
-
-use alloc::string::String;
-use alloc::vec::Vec;
-
-use pdsl_core::storage;
-use parity_codec_derive::{Encode, Decode};
+use pdsl_core::{
+	memory::{
+		string::String,
+	},
+	storage,
+};
 use parity_codec::{Encode, Decode};
 
 /// A peep done by a registered user.

examples/subpeep/src/utils.rs

@@ -5,17 +5,13 @@ use pdsl_core::{
 			ForwardAlloc,
 		},
 	},
-	env::{
-		Env,
-		ContractEnv,
-	},
+	memory::string::String,
 };
 
 use parity_codec::{Encode, Decode};
 use lazy_static::lazy_static;
 use spin::Mutex;
 
-use alloc::string::String;
 
 pub type Address = [u8; 32];