I don't know how can I convert Option<BalanceOf> (subtrate specific type)to u64 (rust primitive types)?

I followed this article( How do you convert between Substrate specific types and Rust primitive types? ), it helped me while converting u64 to Option<BalanceOf using the below function.

    pub fn u64_to_balance_option(input: u8) -> Option<BalanceOf<T>> {

But I also need to convert some Option<BalanceOf> types inside u64 to perform some mathematical operation and then again convert u64 to Option<BalanceOf> to put back inside my storage items.

Thank you

  • Can you share the function signature you want, since your question makes exactly what types you are working with confusing.
    – Shawn Tabrizi
    Mar 28, 2022 at 16:48

1 Answer 1


You'll see that Currency::Balance is bound to AtLeast32BitUnsigned which by being bound to BaseArithmetic is bound to implement TryInto<u64>. Therefore the most obvious code is something like:

pub fn balance_to_u64_option(input: impl TryInto<u64>) -> Option<u64> {

However, balances cannot necessarily be expressed as a u64, so this really isn't such a great plan for production code as it will restrict your pallet to being used only when someone has a small enough balance.

In general, you should aim to do all arithmetic in the native Polkadot types. Currency::Balance is required to implement all the typical arithmetic operations for this reason.

  • Can you please make it more simple for me, I am very new to substrate and rust, Thank you for your response. Mar 28, 2022 at 14:29

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