Fix E0772: Function pointer called with wrong number of arguments

Sat, 25 Apr 2026 17:32:04 +0800

1. Symptoms

The Rust compiler emits error E0772 when attempting to invoke a function pointer with a mismatched argument count. This error occurs during the type-checking phase of compilation.


The compiler clearly indicates the discrepancy between the expected argument count and the actual number provided. In this case, the function pointer expects 2 arguments, but 3 were supplied.

**Additional symptom patterns:**

```rust
// Example 1: Too few arguments
error[E0772]: this function takes 3 argument(s) but 1 argument(s) were supplied
 --> src/main.rs:10:20
 |
10 | let result = func_ptr(arg1);
 | ^^^^^^^^^ -- expected 2 more argument(s)

// Example 2: Calling with zero arguments when one is expected
error[E0772]: this function takes 1 argument(s) but 0 argument(s) were supplied
 --> src/main.rs:15:5
 |
15 | func_ptr();
 | ^^^^^^^^

// Example 3: With closures and function pointers
error[E0772]: this function takes 2 argument(s) but 3 argument(s) were supplied
 --> src/main.rs:20:14
 |
20 | (func_ptr)(1, 2, 3);
 | ^^^^^^^^ ---------

The error message always follows the pattern: this function takes N argument(s) but M argument(s) were supplied, where N is the expected count and M is the actual count.

Function-Calls on ErrorVault — Developer Error Code Dictionary

Fix E0772: Function pointer called with wrong number of arguments

1. Symptoms

The Rust compiler emits error E0772 when attempting to invoke a function pointer with a mismatched argument count. This error occurs during the type-checking phase of compilation.