Assert¶

Terminates the program if a condition evaluates to false.

Module: Std

Summary¶

Assert(
    condition: bool,
    message: char8[],
    file: char8[] = #file,
    function: char8[] = #function,
    line: uint = #line,
    column: uint = #column
)

Description¶

Assert verifies that a condition is true.

If the condition evaluates to false, an error message is printed containing:

The assertion message
Source file
Line number
Column number
Function name

After printing the diagnostic information, the program exits with status code 2.

This function is intended for validating assumptions and detecting programming errors during development.

Parameters¶

Parameter	Description
`condition`	Expression that must evaluate to `true`.
`message`	Message displayed when the assertion fails.
`file`	Source file where the assertion occurred. Automatically provided by `#file`.
`function`	Function where the assertion occurred. Automatically provided by `#function`.
`line`	Source line where the assertion occurred. Automatically provided by `#line`.
`column`	Source column where the assertion occurred. Automatically provided by `#column`.

Example¶

import Std::Assert;
import Std::Io::Print;

func Main() {
    let value = 42;

    Assert(value > 0, "value must be positive");

    Print("Assertion passed");
}

Output:

Assertion passed

Failed Assertion Example¶

import Std::Assert;
import Std::Io::Print;

func Main() {
    let value = -1;

    Assert(value > 0, "value must be positive");
}

Output:

Assertion failed: value must be positive
--> Main.rux:7:11
    in function Main

Platform Notes¶

Assert is available on all supported platforms.

Platform	Supported
Linux	yes
Windows	yes
macOS	Planned
BSD	yes
Illumos	yes

Exit Code¶

Code	Meaning
`2`	Assertion failed