컴파일 시점 검증과 @compileError

Zig lets you reject bad usage while the code compiles. The built-in @compileError stops the build with a message you write. 🛑

@compileError takes a comptime string and aborts compilation, printing exactly that text so the caller knows what went wrong.

Inside a comptime branch you can reject unwanted types. Here only integers pass; anything else hits @compileError at the call site.

A comptime check runs when the function is instantiated, so the error appears where the wrong type was actually passed in.

For simple invariants, comptime assert stops the build when a condition is false, similar to a runtime assert but earlier.

Use @hasDecl to confirm a type provides a method or constant before you call it, then fail clearly if it does not.

Likewise @hasField tells you whether a struct has a named field, which is handy when validating shapes at compile time.

Combine @typeName with std.fmt to embed the offending type in your message, giving callers a precise, readable error.

The ++ operator concatenates comptime strings, so you can compose detailed error text without any heap allocation.

All of this validation happens during compilation. A program that builds successfully carries no checking overhead at run time. ⚡

Comptime validation turns a possible crash into a friendly build-time message, so misuse is caught early and explained well.

You want to abort the build with a custom message when a type is unsupported. What do you call?

@compileError plus checks like @hasDecl and comptime assert reject bad usage during the build, with zero runtime cost. 🎯