Chapter 0 --- Global Module and Meta Information

In this chapter, you will bootstrap the MySTL library by implementing its global module entry point and a meta information module. These components establish the foundation of a modular C++23 library and define the public interface that other modules and user code will rely on.

⚠️ Important: All tasks in this chapter must follow the specified interfaces exactly. Module names, exported symbols, and structure must not be altered. Any deviation may cause module linkage failures or test incompatibilities.

Directory Structure

Organize your files as follows:

mystl/
└── chapter0/
    ├── global.cppm
    └── metaInfo/
        └── metaInfo.cppm

1. Global Module

Objective

Implement the global module for MySTL.
This module serves as the primary entry point of the library and aggregates public-facing modules for convenient importing.

After implementation, users should be able to write:

import mySTL;

to access exported functionality.

Requirements

• Create a C++23 module named: mySTL
• Re-export the meta information module named: mySTL.metaInfo

Strict Constraints

Do not:

• Add any additional code
• Declare types, functions, or variables
• Modify the module name
• Change the export behavior
• Include implementation details

The global module must remain minimal and act purely as a module aggregator.

Example Usage

import mySTL;
import mySTL.metaInfo;

// Meta information is now accessible.

2. Meta Information Module

Objective

Implement the meta information module that describes the library.
Providing structured metadata is a common practice in production-grade libraries and helps users quickly identify the library version and purpose.

Requirements

Create a module named:

mySTL.metaInfo

Follow the reference interface precisely and provide the following metadata.

Library Name

Accessible via:

mySTL::metaInfo::name

Expected value:

MySTL

Version Information

Accessible via:

mySTL::metaInfo::version.major
mySTL::metaInfo::version.minor
mySTL::metaInfo::version.patch

Expected version:

0.1.0

Description

Accessible via:

mySTL::metaInfo::description

Expected value:

My Standard Template Library

Strict Constraints

• All names, types, and values must match the reference implementation exactly.
• Do not introduce extra symbols.
• Do not modify the interface.
• Avoid unrelated code.

Failure to comply may result in:

• ABI incompatibility\
• Linker errors\
• Automated test failures

Example Usage

import mySTL.metaInfo;
#include <iostream>

int main() {
    std::cout << mySTL::metaInfo::name << "\n";

    std::cout << mySTL::metaInfo::version.major << "."
              << mySTL::metaInfo::version.minor << "."
              << mySTL::metaInfo::version.patch << "\n";

    std::cout << mySTL::metaInfo::description << "\n";

    return 0;
}

Expected Output

MySTL
0.1.0
My Standard Template Library

Run Unit Tests

You can run unit tests on your code using the following command:
xmake f -m release
xmake run chapter0_tests
You can also run unit tests on the reference code to compare it with your implementation:
xmake f -m debug
xmake run chapter0_tests