C83Standard

C, Cpp, CppCli, DspC, ECpp standards identification macros for C and C++

3rd edition of the library

part of the C83Project
support for 8.3 file naming conventions with the exception of the main include and code files
support CKR(K&R C) and higher editions

Overview

C83Standard is a lightweight, portable, header‑based C/C++ utility library designed to detect the active language standard used by the compiler. It supports strict 8.3 filename conventions, making it suitable for embedded systems, legacy toolchains, DOS‑based environments, and cross‑platform builds.

Features

• C language standards from CKR(K&R C) to C23
• Detects hosted / freestanding C standard
• C++ language standards from CPPPRE(pre-standard) to CPP23
• C++ CLI language standards from CPPCLIPRE(pre-standard) to CPPCLI
• Detects Embedded C++ mode
• DSP‑C (reserved for future use)

Design Goals

Primary Objectives

• Provide a unified, compiler‑agnostic way to detect language standards.
• Work with old, modern, and embedded compilers.
• Maintain 8.3 filename compatibility.
• Avoid dependencies and remain header‑only (except for the version function).

Key Principles

• Simplicity: Easy to integrate and use.
• Predictability: All macros follow consistent naming conventions.
• Portability: Works across GCC, Clang, MSVC, Turbo C++, and embedded compilers.
• Minimalism: Only preprocessor logic, no runtime overhead except for version function.
• Transparency: Exposes all detected values via simple macros.

Repository Structure

Filename	Description
C83Standard.h	Main include file, exposes version API
C83Standard.c	Implementation of version function
PC.h	C standard detection macros
PCpp.h	C++ standard detection macros
PCppCli.h	C++/CLI standard detection macros
PDspC.h	DSP‑C placeholder definitions
PECpp.h	Embedded C++ detection macros
License.txt	MIT License file
README.md	Usage examples and project notes

C Standard Detection (PC.h)

Detection Macros

Macro	Description
C_STD	1 if __STDC__ is defined, otherwise 0
C_VERSION	Numeric C standard version
C_STD_HOSTED	1 hosted, 0 freestanding, -1 unknown

Supported C Standards

Macro	Meaning
CKR	K&R C (pre-ANSI) or Non standard C
C89	ANSI C (C89/C90)
C95	ISO C95
C99	ISO C99
C11	ISO C11
C17	ISO C17
C23	ISO C23
NOC	Not a C environment (e.g., compiling as C++)

C++ Standard Detection (PCpp.h)

Detection Macros

Macro	Description
CPP_VERSION	Numeric C++ standard version

Supported C++ Standards

Macro	Meaning
CPPPRE	Pre-standard C++
CPP98	C++98
CPP03	C++03
CPP11	C++11
CPP14	C++14
CPP17	C++17
CPP20	C++20
CPP23	C++23
NOCPP	Not a C++ environment (e.g., compiling as C)

Alias Macros

Alias	Original Macro
CXXPRE	CPPPRE
CXX98	CPP98
CXX03	CPP03
CXX11	CPP11
CXX14	CPP14
CXX17	CPP17
CXX20	CPP20
CXX23	CPP23
NOCXX	NOCPP

C++/CLI Standard Detection (PCppCli.h)

Detection Macros

Macro	Description
CPPCLI_VERSION	Numeric C++ CLI standard version

Supported C++/CLI Standards

Macro	Meaning
CPPCLIPRE	Pre-standard C++/CLI
CPPCLI	C++/CLI
NOCPPCLI	Not a C++ CLI environment

Alias Macros

Alias	Original Macro
CXXCLIPRE	CPPCLIPRE
CXXCLI	CPPCLI
NOCXXCLI	NOCPPCLI

Embedded C++ Detection (PECpp.h)

Detection Macros

Macro	Description
ECPP_VERSION	Numeric EC++ version

Supported Values

Macro	Meaning
NOECPP	Embedded C++ not active

DSP‑C Detection (PDspC.h)

Currently only a placeholder. Reserved for future expansion.

Usage

Detecting C Standard

To check which C standard is being used, you can use the predefined macros in conditional compilation blocks.

C Version Detection Example (Conditional Compilation)

#if C_VERSION == CKR
    ...
    CKR code
    ...
#elif C_VERSION == C89
    ...
    C89 code
    ...
#elif C_VERSION == C95
    ...
    C95 code
    ...
#elif C_VERSION == C99
    ...
    C99 code
    ...
#else
    ...
    other code
    ...
#endif

Hosted vs Freestanding Example (Conditional Compilation)

#if C_STD_HOSTED == 1
...
hosted code
...
#elif C_STD_HOSTED == 0
...
freestanding code
...
#else
...
unknown environment code
...
#endif

Detecting C++ Standard

To check which C++ standard is being used, you can use the predefined macros in conditional compilation blocks.

C++ Version Detection Example (Conditional Compilation)

#if CPP_VERSION == CPPPRE
    ...
    CPPPRE code
    ...
#elif CPP_VERSION == CPP98
    ...
    CPP98 code
    ...
#elif CPP_VERSION == CPP11
    ...
    CPP11 code
    ...
#else
    ...
    other code
    ...
#endif

or using alias
 
#if CXX_VERSION == CXXPRE
    ...
    CPPPRE code
    ...
#elif CXX_VERSION == CXX98
    ...
    CPP98 code
    ...
#elif CXX_VERSION == CXX11
    ...
    CPP11 code
    ...
#else
    ...
    other code
    ...
#endif

Cross Compilation Example (Conditional Compilation)

#if C_VERSION >= C17 || CPP_VERSION >= CPP17
    ...
    Cross code
    ...
#endif

Detecting C++/CLI Standard

To check which C++/CLI standard is being used, you can use the predefined macros in conditional compilation blocks.

C++ CLI Version Detection Example (Conditional Compilation)

#if CPPCLI_VERSION == CPPCLIPRE
    ...
    CPPCLIPRE code
    ...
#elif CPPCLI_VERSION == CPPCLI
    ...
    CPPCLI code
    ...
#else
    ...
    other code
    ...
#endif

or

#if CXXCLI_VERSION == CXXCLIPRE
    ...
    CPPCLIPRE code
    ...
#elif CXXCLI_VERSION == CXXCLI
    ...
    CPPCLI code
    ...
#else
    ...
    other code
    ...
#endif

Detecting Embedded C++

To check if Embedded C++ mode is active, you can use the predefined macros in conditional compilation blocks.

Embedded C++ Detection Example (Conditional Compilation)

#if ECPP_VERSION > NOECPP
    ...
    ECPP code
    ...
#endif

or

#if ECXX_VERSION > NOECXX
    ...
    ECPP code
    ...
#endif

Example of versions detection

printf("C83STANDARD Library version = %ld %ld\r\n", C83STANDARD_DATE(), C83STANDARD_VERSION());
printf("\r\n");

/* versions detection 1 */
printf("First C               = %ld\r\n", CKR);
printf("Last C                = %ld\r\n", C23);
printf("Current C             = %ld\r\n", C_VERSION);
printf("\r\n");

printf("First CPP             = %ld\r\n", CPPPRE);
printf("Last CPP              = %ld\r\n", CPP23);
printf("Current CPP           = %ld\r\n", CPP_VERSION);
printf("\r\n");

printf("First CXX             = %ld\r\n", CXXPRE);
printf("Last CXX              = %ld\r\n", CXX23);
printf("Current CXX           = %ld\r\n", CXX_VERSION);
printf("\r\n");

printf("First CPP CLI         = %ld\r\n", CPPCLIPRE);
printf("Last CPP CLI          = %ld\r\n", CPPCLI);
printf("Current CPP CLI       = %ld\r\n", CPPCLI_VERSION);
printf("\r\n");

printf("First CXX CLI         = %ld\r\n", CXXCLIPRE);
printf("Last CXX CLI          = %ld\r\n", CXXCLI);
printf("Current CXX CLI       = %ld\r\n", CXXCLI_VERSION);
printf("\r\n");

printf("Current ECPP          = %ld\r\n", ECPP_VERSION);
printf("\r\n");

printf("Current ECXX          = %ld\r\n", ECXX_VERSION);
printf("\r\n");

/* versions detection 2 */
printf("stdc                  = %d\r\n",  GET_C_STD());
printf("c version             = %ld\r\n", GET_C_VERSION());
printf("c version year        = %ld\r\n", GET_C_VERSION_YEAR());
printf("stdc hosted           = %d\r\n",  GET_C_STD_HOSTED());
printf("\r\n");

printf("cpp version           = %ld\r\n", GET_CPP_VERSION());
printf("cpp version year      = %ld\r\n", GET_CPP_VERSION_YEAR());
printf("\r\n");

printf("cxx version           = %ld\r\n", GET_CXX_VERSION());
printf("cxx version year      = %ld\r\n", GET_CXX_VERSION_YEAR());
printf("\r\n");

printf("cpp cli version       = %ld\r\n", GET_CPPCLI_VERSION());
printf("cpp cli version year  = %ld\r\n", GET_CPPCLI_VERSION_YEAR());
printf("\r\n");

printf("cxx cli version       = %ld\r\n", GET_CXXCLI_VERSION());
printf("cxx cli version year  = %ld\r\n", GET_CXXCLI_VERSION_YEAR());
printf("\r\n");

printf("ecpp version          = %ld\r\n", GET_ECPP_VERSION());
printf("\r\n");

printf("ecxx version          = %ld\r\n", GET_ECXX_VERSION());
printf("\r\n");

Compiler Compatibility

Compiler	C Detection	C++ Detection	C++/CLI Detection	Embedded C++ Detection	Notes
GCC	Yes	Yes	No	No
Clang	Yes	Yes	No	No
MSVC	Yes	Yes	Yes	No
Turbo C++	Yes	Yes (Uses CPPPRE)	No	No	Limited modern support
Embedded Compilers	Yes / (Varies)	Yes / (Varies)	No	Yes	Check specific compiler

Best Practices

• Use macros for conditional compilation.
• Print detected versions for debugging.
• Use aliases (CXX, CPP) interchangeably.

Avoid

• Mixing C and C++ detection macros incorrectly.

License

This library is licensed under the MIT License. See the LICENSE file for details.

Updates

YYYY MM DD	XX YY ZZ WW	Brief description of updates
2025 10 29		Fixed error when detecting __cplusplus for Turbo C++
2025 10 29		NOC, NOCPP/NOCXX, NOCPPCLI/NOCXXCLI defines added
2025 10 30		C.h renamed to PC.h
2025 10 30		Cpp.h renamed to PCpp.h
2025 10 30		CppCli.h renamed to PCppCli.h
2025 10 30		DspC.h renamed to PDspC.h
2025 10 30		ECpp.h renamed to PECpp.h
2025 10 30		Description bug fixed
2026 01 15		Updated README.md for clarity and completeness
2026 01 15		Added support for Legacy MSVC as C89
2026 01 15		Added NOECPP and NOECXX identification macros for ECPP
2026 01 16		Removed support for Legacy MSVC as C89, bug fixed
2026 01 17	26 00 01 01	Added full support for Legacy MSVC as C89_MSVC
2026 01 17	26 00 01 01	Project versioning modified
2026 01 19	26 00 01 02	Modified comment for CKR (K&R C or non-standard C) in PC.h
2026 01 19	26 00 01 02	Modified comment in Legacy MSVC in PC.h
2026 01 19	26 00 01 02	Improved detection of legacy C89_MSVC from version _MSC_VER 1900 (VS2015+)
2026 01 19	26 00 01 03	Supported C Standards table actualized
2026 01 19	26 00 02 01	C89_MSVC definitively removed as nonsystematic option