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homeless-try

Compiler
This rule is enabled as an error by default.

What This Rule Does​

Checks for try statements used outside of error-returning functions.

As a compiler-level lint, this rule checks for errors also caught by the Zig compiler.

Examples​

Examples of incorrect code for this rule:

const std = @import("std");

var not_in_a_function = try std.heap.page_allocator.alloc(u8, 8);

fn foo() void {
  var my_str = try std.heap.page_allocator.alloc(u8, 8);
}

fn bar() !void {
  const Baz = struct {
    property: u32 = try std.heap.page_allocator.alloc(u8, 8),
  };
}

Examples of correct code for this rule:

fn foo() !void {
  var my_str = try std.heap.page_allocator.alloc(u8, 8);
}

Zig allows try in comptime scopes in or nested within functions. This rule does not flag these cases.

const std = @import("std");
fn foo(x: u32) void {
  comptime {
    // valid
    try bar(x);
  }
}
fn bar(x: u32) !void {
  return if (x == 0) error.Unreachable else void;
}

Zig also allows try on functions whose error union sets are empty. ZLint does not respect this case. Please refactor such functions to not return an error union.

const std = @import("std");
fn foo() !u32 {
  // compiles, but treated as a violation. `bar` should return `u32`.
  const x = try bar();
  return x + 1;
}
fn bar() u32 {
  return 1;
}

Configuration​

This rule has no configuration.