Understanding the Solana Error “No Function or Related Item Named Create_type”
As a developer builds applications on the Solana blockchain, it is not uncommon to encounter errors related to smart contract creation. One such error is the “No Function or Related Item Named Create_type” error, which can occur when trying to use a custom type defined in a Solana application.
Problem: Error E0599
In the code snippet provided:
use solana_program::program_error::{error, ErrorKind};
use solana_program::pubkey::Pubkey;
use solana_type::create_type;
// Define a custom type here
pub fn main() -> Result<(), error::Error> {
// Here is your program logic...
// Create a new operation using a custom type
let tx = create_type!(T) as &_, 10u64; // T is your custom type, and "as &_"
}
The error occurs because there is no “create_type!” function in the Solana SDK. Instead, you should use “program_error::ErrorKind::CustomType” to resolve this specific error.
Bug Fix
To fix the error, you need to define a custom type and use it when creating operations. Here is the updated version of the code:
use solana_program::program_error::{error, ErrorKind};
use solana_program::pubkey::Pubkey;
use std::mem;
// Define a custom type here
pub fn main() -> Result<(), error::Error> {
// Create a new operation using a custom type
let tx = create_type!(T) as &_, 10u64; // T is your custom type, and "as &_"
// Check if the operation was successfully created
match tx {
Ok(_) => println!("Operation successfully created"),
Err(err) => error!("Failed to create operation", error),
}
}
Understanding Custom Types
You can define custom types in Solana using the “create_type!” macro. This macro is used to generate code for creating custom types.
Here is an example of a basic custom type:
use solana_type::create_type;
pub type MyCustomType = u8;
With this definition, we can use it to create transactions:
pub fn create_transaction() -> ProgramResult {
// Create a new transaction using a custom type
let tx = MyCustomType::new(10);
ok(())
}
Conclusion
In this article, we learned how to fix the Solana error “no function or related element named create_type exists”. By defining your own custom types and using them to create transactions, you can build more complex applications on the blockchain.
Remember to always check the official Solana documentation for the latest information on programming languages and types.