bevyengine/bevy · error · FunctionOverloadError

argument signature `{:?}` has too many arguments (max {})

Error message

argument signature `{:?}` has too many arguments (max {})

What it means

FunctionOverloadError::TooManyArguments — the overload's argument signature has more parameters than ArgCount::MAX_COUNT allows, so it cannot be represented. Reduce the number of arguments in the function signature.

Source

Thrown at crates/bevy_reflect/src/func/error.rs:60

/// [`DynamicFunction`]: crate::func::DynamicFunction
/// [`DynamicFunctionMut`]: crate::func::DynamicFunctionMut
pub type FunctionResult<'a> = Result<Return<'a>, FunctionError>;

/// An error that occurs when attempting to add a function overload.
#[derive(Debug, Error, PartialEq)]
pub enum FunctionOverloadError {
    /// A [`SignatureInfo`] was expected, but none was found.
    ///
    /// [`SignatureInfo`]: crate::func::info::SignatureInfo
    #[error("expected at least one `SignatureInfo` but found none")]
    MissingSignature,
    /// An error that occurs when attempting to add a function overload with a duplicate signature.
    #[error("could not add function overload: duplicate found for signature `{0:?}`")]
    DuplicateSignature(ArgumentSignature),
    /// An attempt was made to add an overload with more than [`ArgCount::MAX_COUNT`] arguments.
    ///
    /// [`ArgCount::MAX_COUNT`]: crate::func::args::ArgCount
    #[error(
        "argument signature `{:?}` has too many arguments (max {})",
        0,
        ArgCount::MAX_COUNT
    )]
    TooManyArguments(ArgumentSignature),
}

/// An error that occurs when registering a function into a [`FunctionRegistry`].
///
/// [`FunctionRegistry`]: crate::func::FunctionRegistry
#[derive(Debug, Error, PartialEq)]
pub enum FunctionRegistrationError {
    /// A function with the given name has already been registered.
    ///
    /// Contains the duplicate function name.
    #[error("a function has already been registered with name {0:?}")]
    DuplicateName(Cow<'static, str>),
    /// The function is missing a name by which it can be registered.

View on GitHub (pinned to 396ca72708)

Solutions

1. Reduce the number of parameters to within the maximum
2. Group parameters into a single struct parameter

When it happens

Trigger: Thrown at crates/bevy_reflect/src/func/error.rs:60 when the library encounters an invalid state.

Common situations: See trigger scenarios.

AI-assisted analysis of bevyengine/bevy@396ca72708 (2026-08-20). Data as JSON: /api/errors/b89cc5bc48c997f2. Report an issue: GitHub.