Rust error E0615: attempted to take value of method on type

What it meansYou wrote a method name without parentheses, so Rust thinks you want a field with that name. Add () to call it.

What rustc prints

error[E0615]: attempted to take value of method `method` on type `Foo`
  --> main.rs:12:3
   |
12 | f.method; // error: attempted to take value of method `method` on type `Foo`
   |   ^^^^^^ method, not a field
   |
help: use parentheses to call the method
   |
12 | f.method(); // error: attempted to take value of method `method` on type `Foo`
   |         ++

Real output of rustc 1.99.0 compiling the official example below (2021 edition). Your names and line numbers will differ; the first line is the part to match.

Why it happens

v.len instead of v.len().
A getter method with the same name as a private field.

How to fix it

1. Call the method

let n = v.len();

Other wordings of this error

attempted to take value of method on type, use parentheses to call the method

E0615Types and traits

Activein rustc 1.99.0

8related errors linked below

The compiler team's explanation

Attempted to access a method like a field.

Erroneous code example:

struct Foo {
    x: u32,
}

impl Foo {
    fn method(&self) {}
}

let f = Foo { x: 0 };
f.method; // error: attempted to take value of method `method` on type `Foo`

If you want to use a method, add () after it:

f.method();

However, if you wanted to access a field of a struct check that the field name is spelled correctly. Example:

println!("{}", f.x);

From rustc --explain E0615 (1.99.0), part of the Rust project, MIT or Apache-2.0. Official page.

Up next

Often hit nextE0308: mismatched typesA related error from the same family.Read it next →

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