Metaprogramming

Modules
	Block Wrapping
	Protected Blocks
	Exception Handling

Detailed Description

Advanced C metaprogramming macros for complex control flow patterns.

The meta module provides compile-time and runtime control flow facilities built on creative uses of for loops and other C constructs. The primary tool is blkWrap(), which enables automatic cleanup and resource management patterns similar to RAII in C++.

Primary Use Case - blkWrap():

The blkWrap() macro executes code before and after a block, guaranteeing cleanup even if the block exits early with break or continue. This is lightweight and suitable for most situations:

blkWrap(mutex_lock(&mtx), mutex_unlock(&mtx)) {
    // critical section - mutex is always unlocked on exit
    if (condition) break;  // early exit still runs cleanup
}

Advanced Features:

For more complex scenarios involving nested unwinding or exception-like behavior, the module also provides protected blocks (pblock) and try/catch constructs (ptTry/ptCatch/ptFinally). However, these are heavyweight operations with significant performance implications:

• Add measurable execution overhead from setjmp/longjmp
• Inhibit compiler optimizations throughout the protected region
• Consume large amounts of stack space for each nested level

Use these advanced features sparingly, only when simpler alternatives are insufficient.

Compile-Time Feature Inhibition:

The module includes a facility for compile-time checks that prevent use of specific language features (like return) within certain blocks, helping catch errors early.

See Block Wrapping for block wrapping and basic control flow, Protected Blocks for protected blocks, and Exception Handling for exception handling.