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Version: 1.0
For the complete Mojo documentation index, see llms.txt. Markdown versions of all pages are available by appending .md to any URL (e.g. /docs/manual/basics.md).

struct_field_count

struct_field_count[T: AnyType]() -> Int

Deprecated: use reflect[T]().field_count() instead.

Returns the number of fields in struct T.

This function works with both concrete types and generic type parameters.

Note: For best performance, assign the result to a comptime variable to ensure compile-time evaluation: comptime count = struct_field_count[T]()

Example:

from std.reflection import struct_field_count

struct MyStruct:
    var x: Int
    var y: Float64

def count_fields[T: AnyType]() -> Int:
    return struct_field_count[T]()

def main():
    print(count_fields[MyStruct]())  # Prints field count

Deprecated: Use reflect[T]().field_count() instead.

Constraints:

T must be a struct type. Passing a non-struct type results in a compile-time error.

Parameters:

Returns:

Int: The number of fields in the struct.