Dwight J. Browne

The standard libraries of Rust, C, and Java serve as the foundation for performing essential tasks in general programming, such as input/output operations, error handling, and interacting with the underlying operating system. The design philosophies of these languages reflect not only their historical context and original purposes but also the evolving needs and challenges of software development. 

C, developed in the early 1970s, was designed as a high-level replacement for assembly language, aimed at system programming and the development of operating systems. Its standard library is minimalistic and procedural, focusing on providing a thin layer of abstraction over hardware to maximize efficiency and control. This design choice reflects C's emphasis on performance and flexibility, essential in contexts where direct manipulation of memory and hardware resources is required. 

Java, conceived in the mid-1990s, introduced the specious "write once, run everywhere" paradigm, emphasizing portability and ease of use. Its standard library, rich in functionality, is designed around an extensive object-oriented architecture that abstracts away the complexities of different operating systems and hardware platforms. This approach allows Java applications to be platform-independent, facilitating development for the burgeoning web and enterprise domains, where applications need to run across various environments without modification. 

Rust, emerging in the 2010s, was designed with the primary goal of preventing memory leaks and ensuring thread safety, addressing some of the critical issues inherent in system programming with C and C++. Its standard library reflects a balance between performance and safety, employing modern programming language features such as ownership, types, and explicit error handling to manage resources efficiently and safely. Rust's design philosophy underscores the importance of memory safety without sacrificing performance, catering to contemporary needs for reliable and concurrent software development. 

The evolution from C to Java to Rust illustrates a trajectory from direct hardware manipulation and efficiency, through portability and ease of use, to memory safety and concurrency. Each language's standard library encapsulates its core principles, offering a tailored suite of functionalities that support its unique design goals. These libraries not only facilitate the basic tasks of programming but also guide developers towards the idiomatic practices of each language, shaping the way software is written and the kind of problems that can be solved efficiently in each ecosystem.

But What about C++?

Input/Output Operations

Rust: Rust's standard library provides a modular and comprehensive approach to I/O operations, distinguishing between synchronous and asynchronous I/O through different modules (std::io for synchronous I/O and async-std or tokio for asynchronous I/O in the ecosystem). Rust emphasizes safety and zero-cost abstractions, offering both high-level and low-level access to I/O operations, with strong typing and error handling to prevent common bugs like buffer overflows. 

C: C's approach to I/O is provided through the Standard C Library (e.g., stdio.h for file and console I/O). It's more procedural and less abstracted, giving programmers direct, low-level access to system resources. C's I/O operations are simple and flexible but require the programmer to be more cautious about error handling and resource management to avoid security vulnerabilities and memory leaks. 

 Java: Java uses a comprehensive, object-oriented model for I/O, encapsulated within the java.io and java.nio (New I/O) packages, among others. The design is highly abstracted, with a rich hierarchy of classes and interfaces that cover a wide range of I/O needs, including file I/O, networking, and inter-process communication. Java's approach emphasizes ease of use, portability, and safety, with built-in mechanisms for managing resources (e.g., try-with-resources statement) and handling errors. 

Unlike C and Rust, which allow developers direct control over memory management, Java operates within the constraints of the Java Virtual Machine (JVM). This architecture doesn't afford the same level of direct memory manipulation. While the JVM's Just-In-Time (JIT) compiler performs optimizations to enhance execution speed, it's important to temper expectations regarding performance. The notion that Java can match the speed of lower-level languages on all fronts is a misconception some enthusiasts may claim. Though JIT optimizations can significantly improve performance, Java may not always achieve the same efficiency levels as C or Rust, which provide closer hardware interaction and more granular control over memory and execution. 

Error Handling

Rust: Rust introduces a novel approach to error handling that distinguishes between recoverable errors (Result type) and unrecoverable errors (panic). This model encourages explicit handling of errors, making Rust programs more reliable and predictable by design. The compiler enforces handling of recoverable errors, aiding in the prevention of common mistakes.

C: Error handling in C is more manual and less structured. Functions typically return error codes or null pointers to indicate failure, and it's up to the programmer to check these values and handle errors appropriately. This approach provides flexibility but increases the risk of overlooking error handling, potentially leading to undefined behavior or security vulnerabilities. 

 Java: Java uses exceptions to manage errors and exceptional situations. The language differentiates between checked exceptions (which must be either caught or declared to be thrown) and unchecked exceptions (which do not need to be explicitly handled). This model encourages robust error handling and recovery strategies but has been critiqued for potentially leading to verbose code.

System Interactions

Rust: Rust provides safe abstractions for interacting with system-level resources through its standard library, with a focus on ownership and types to manage resources (like memory, files, and threads) safely and efficiently. Rust also allows unsafe code blocks for direct system calls when necessary, but this is discouraged unless absolutely needed. 

 C: Given its origins and purposes as a systems programming language, C offers very direct and comprehensive access to system resources and calls, with minimal abstraction. This allows for high performance and flexibility but requires a thorough understanding of the underlying system and careful resource management. 

 Java: Java abstracts away most of the system-level details from the programmer, running on the Java Virtual Machine (JVM) to ensure portability across different platforms. System interactions in Java are managed through high-level APIs, which sacrifice some performance and control in favor of safety, simplicity, and cross-platform compatibility.  Essentially, you have a much lower chance of crashing the server or VM with a Java program.     

So.. What does all of this mean?

Rust aims for safety and concurrency without sacrificing performance. It can''t beat C/C++ just yet but the GCC backend   (also this) might just fix that. 

C offers maximum control and efficiency with minimal abstractions, and Java focuses on portability, ease of use, and robustness through high-level abstractions.

These approaches reflect the distinct goals and use cases each language is optimized for. Implementing unsafe Rust code involves directly bypassing the safety guarantees enforced by the Rust compiler.
These safety guarantees are designed to prevent a wide range of common bugs and security vulnerabilities, such as null pointer dereferencing, buffer overflows, and data races in concurrent code.

Postscript:

BTW, Java has often been humorously referred to as the COBOL of the 21st century, with some advising to avoid it entirely. However, this perspective overlooks Java's widespread adoption and suitability for various applications, from enterprise software to Android apps. While C and C++ remain preferred languages for mission-critical applications due to their performance and system-level control—powering systems like the Chrome browser, the Linux kernel, and various virtual machines and databases—it's not accurate to dismiss Java's capabilities outright. Writing such systems in Java may be less conventional, akin to the novelty of driving a car with your feet; it's technically possible but not necessarily optimal given the alternatives. Each language has its domain of excellence, and Java's role in modern software development, particularly in areas requiring cross-platform compatibility and rapid development cycles, remains significant.

Acknowledging a dismissal of Java throughout my professional career was, in hindsight, somewhat like  a jazz musician who refuses to conform to commercial tastes—a choice that, while artistically fulfilling, might not have been the most financially prudent. This analogy captures the essence of prioritizing personal or technical preferences over broader market demands. Just as the musician might miss out on lucrative opportunities by avoiding mainstream genres, I've realized that overlooking Java—a language with vast applicability, from enterprise solutions to mobile applications—may have limited my career's financial potential. This reflection isn't about regret over the path chosen but rather an acknowledgment of the balance between following one's professional inclinations and the practicalities of the job market. But.... I'm sticking to my guns on this and will bet the farm on Rust.   I'm not going to be stuck maintaining legacy code.

Some References