The shit that makes you want to throw your laptop
Look, nobody migrates to Zig because it's "better." You migrate because your current toolchain is making you miserable in very specific ways, and Zig fixes those exact problems while introducing completely new ways to hate your life.
Cross-Compilation Hell
Cross-compilation in C++ is a nightmare that has broken more teams than I can count.
You know the drill
- Docker containers, custom toolchains, arcane CMake flags, and sacrificing small animals to the build gods just to get ARM binaries that might work.
Zig Cross-Compilation Targets: Out of the box, Zig supports x86_64, ARM, AArch64, i386, RISC-V, and Web
Assembly across Linux, macOS, Windows, FreeBSD, and more
- all without external toolchains.
Zig actually fixed this.
Like, properly fucking fixed it. zig build-exe main.zig -target arm-linux and you're done. No Docker containers eating your RAM, no hunting down the right cross-compiler version, no CMake files that look like they were written by someone having a stroke. TigerBeetle's team builds their financial database for multiple platforms with one command.
I tested this myself
- it just works. First time in 15 years of C++ that cross-compilation didn't make me want to change careers.
Template Hell
C++ templates are where productivity goes to die. You've seen it: 400-line error messages from std::map<int, std::vector<std::string>> because you forgot a const somewhere.
Template error messages are basically cryptographic puzzles written by sadists.
Zig's comptime does the same generic programming but with error messages written by humans.
When it breaks, you can actually figure out why. The Zig Language Reference explains this in detail, and Andrew Kelley's blog post shows how comptime eliminates template complexity.
fn GenericHashMap(comptime K: type, comptime V: type) type {
return struct {
// Clear, debuggable generic implementation
// No template instantiation mysteries
};
}
Memory Management Transparency
Unlike C where malloc might be hidden in library calls, or C++ where new can be overloaded, Zig's explicit allocator pattern makes every allocation visible:
Allocator Interface Pattern: Every allocation goes through `std.mem.
Allocator`, making memory usage explicit and allowing arena, page, fixed-buffer, and custom allocator strategies.
var list = std.ArrayList(i32).init(allocator);
defer list.deinit(); // Memory management is obvious
This transparency proved crucial for embedded teams where every byte matters and hidden allocations were causing mysterious crashes.
The Zig allocator design and MicroZig framework show how this works in practice.
The official memory documentation explains why explicit allocation matters.
Migration Patterns That Actually Work
The Only Migration Strategy That Works
Don't try to rewrite everything at once.
You'll fail, your team will hate you, and you'll be back to C++ in three months. The teams that actually ship code do this:
## Step 1:
Use Zig as C compiler
zig cc -c legacy_module.c
## Step 2: Replace individual modules
zig build-exe main.zig legacy_module.c
Start with using Zig to compile your existing C code.
No rewriting, no new syntax, just a different compiler. Once you trust that Zig won't break your shit, then maybe start converting one module at a time. The Zig as a C Compiler post explains this approach, and Uber's migration story shows how they used Zig to cross-compile ARM infrastructure.
Library Wrapping Strategy
Instead of rewriting entire C++ libraries, successful teams create Zig wrappers around critical functionality:
const c = @cImport({
@cInclude(\"legacy_graphics.h\");
});
pub fn initRenderer(allocator:
Allocator) !Renderer {
const c_renderer = c.create_renderer();
if (c_renderer == null) return error.Init
Failed;
return Renderer{ .handle = c_renderer };
}
This allows teams to modernize their interfaces while keeping battle-tested C/C++ implementations intact.
What Nobody Tells You About Migration
The Compiler is Slow as Hell
Zig's compiler is fucking slow on large codebases. Not "oh this takes 30 seconds" slow
- I'm talking "go get coffee, maybe lunch" slow. Bun's team documented spending 181 minutes per week just waiting for builds.
That's over 3 hours of staring at a terminal cursing at progress bars that don't move.
The Zig Language Server (ZLS) crashes constantly and doesn't catch basic type errors.
I've had it crash on a simple struct definition. You'll find yourself compiling code just to discover you misspelled a variable name. Coming from CLion catching my fuckups as I type, this feels like programming with vi on a 1980s terminal.
Breaking Changes Every Release
Zig is pre-1.0, which means your code will break with every update. The 0.15.1 release notes list dozens of breaking changes.
Teams regularly spend entire weekends just getting their code to compile again after updates.
Budget 1-2 days of pain every time there's a new release. And by "1-2 days" I mean "however long it takes to figure out that std.debug.panic got moved to std.debug.assert or some other arbitrary API shuffle." This gets old fast when you have actual features to ship.
Tiny Community
The Zig community is tiny compared to C++. Stack Overflow has maybe a dozen answers for complex Zig questions. Most of the time you'll be reading source code on GitHub or asking questions on Ziggit and waiting for someone to respond.
The Zig Discord is more active but still small.
It's isolating compared to the massive C++ ecosystem.
The Unexpected Benefits
Error Handling That Actually Works
Zig's explicit error handling is genuinely better than C++ exceptions or C return codes:
Error Union Flow: Functions return `!
Ttypes where!means "may return an error". Usetryto propagate orcatch` to handle
- no exceptions thrown at runtime.
const result = parse
Config(path) catch |err| switch (err) {
error.FileNotFound => return error.ConfigMissing,
error.ParseError => return error.InvalidConfig,
else => return err,
};
Instead of segfaults at 3am, you get clear error messages that tell you exactly what went wrong. No more hunting through core dumps to figure out why your config parser shit the bed.
CMake Can Go Die
Zig's build system is just Zig code. No weird CMake DSL, no autotools black magic. It's refreshing:
Build System Architecture: Zig's build system is just Zig code
- no DSL, no XML, no complex dependency graphs.
Define targets, link libraries, and configure builds programmatically.
const exe = b.add
Executable(.{
.name = \"myapp\",
.root_source_file = .{ .path = \"src/main.zig\" },
.target = target,
.optimize = optimize,
});
exe.linkLibC();
I've seen teams throw out hundreds of lines of CMake bullshit and replace it with 50 lines of readable Zig. When your build file makes sense, everything else gets easier. The Zig Build System Guide has examples, and this comparison with CMake shows why developers prefer it.
Performance Reality Check
Compilation Speed Sucks
Forget the marketing about fast compilation. Bun's 850k line codebase takes 90 seconds for debug builds.
That's not fast by any measure. A well-tuned C++ project with ccache and incremental builds often beats this.
The Zig team is working on parallel code generation which improved their own compiler builds by 27%, but large codebases still hurt.
Runtime Performance is Actually Good
Once your code compiles, it runs fast. TigerBeetle's financial database gets C-level performance in production.
Zig doesn't add garbage collection overhead or hidden allocations that kill performance.
Should You Actually Do This?
Here's the real question: are you solving an actual problem with Zig, or just chasing shiny new tech?
Don't migrate if:
- Your team is mostly junior developers
- You have tight deadlines in the next 6 months
- Your C++ code already works fine
- You can't afford months of reduced productivity
Maybe consider it if:
- Cross-compilation is killing your productivity
- Template error messages make you want to quit programming
- You have senior developers who can read source code when docs are missing
- Your management understands this will cost time and money upfront
