pcre2cpp

pcre2cpp is a C++ wrapper for the PCRE2 (Perl Compatible Regular Expressions) library written in C. It provides an object-oriented interface for the original PCRE2 library, while maintaining the same functionality and behavior. DOCS

Features

• Object-oriented interface to PCRE2 10.47.
• Compatible with C++17 and C++20.
• Easy to use regular expression matching with built-in result capturing.

Requirements

• C++17 or newer.
• CMAKE 3.30 or newer

Options

CMAKE Option / #define	Description	Default
PCRE2CPP_ENABLE_CXX20	Enables C++20 features	OFF
PCRE2CPP_DISABLE_ASSERT_ON_RELEASE	Disables assert on release builds	OFF
PCRE2CPP_CHANGE_ASSERTS_TO_EXCEPTIONS	Changes every assert to exceptions in pcre2cpp	OFF
PCRE2CPP_DISABLE_UTF8	Disables UTF-8 support	OFF
PCRE2CPP_DISABLE_UTF16	Disables UTF-16 support	OFF
PCRE2CPP_DISABLE_UTF32	Disables UTF-32 support	OFF

Benchmarks

Compilation (10,000 iterations)

No.	std::regex (ms)	PCRE2 (ms)	pcre2cpp (ms)
1.	72,9598	16,1092	18,5241
2.	57,5480	15,6274	18,1612
3.	57,0869	15,7417	18,3947
4.	57,3934	15,6203	18,6631
5.	44,9840	15,2435	18,5194
6.	57,6100	15,5350	18,3712
7.	43,8009	15,6640	17,8529
8.	57,7913	15,6265	18,1389
9.	59,1878	15,5679	18,3997
10.	57,9911	15,4088	18,0916

regex	Avg (ms)	Overhead (ms)	Per Iteration Avg (ms)	Per Iteration Overhead (ms)
std::regex	56,6353	$${\color{green}{\text{-38,3236}}}$$	0,0057	$${\color{green}{\text{-0,0038}}}$$
PCRE2	15,6144	$${\color{red}{\text{2,6973}}}$$	0,0016	$${\color{red}{\text{0,0003}}}$$
pcre2cpp	18,3117	-	0,0018	-

Match (10,000 iterations)

No.	std::regex (ms)	PCRE2 (ms)	pcre2cpp (ms)
1.	200,0510	7,6231	7,6295
2.	210,2780	7,7943	8,0054
3.	197,5870	7,9984	7,7851
4.	198,2510	7,6498	8,0657
5.	199,3080	8,0307	7,7707
6.	199,4860	7,9415	7,8639
7.	197,2080	8,0802	7,9928
8.	197,3450	7,7989	8,1371
9.	200,0030	7,9187	8,2530
10.	197,8760	7,9905	8,2095

regex	Avg (ms)	Overhead (ms)	Per Iteration Avg (ms)	Per Iteration Overhead (ms)
std::regex	199,7393	$${\color{green}{\text{-191,7680}}}$$	0,0200	$${\color{green}{\text{-0,0192}}}$$
PCRE2	7,8826	$${\color{red}{\text{0,0887}}}$$	0,0008	$${\color{green}{\text{0,0000}}}$$
pcre2cpp	7,9713	-	0,0008	-

Match with all results (10,000 iterations)

No.	std::regex (ms)	PCRE2 (ms)	pcre2cpp (ms)
1.	200,0060	9,7453	11,9927
2.	196,6940	10,7646	12,5312
3.	197,8630	9,8459	16,1080
4.	198,6790	9,5077	12,0731
5.	198,5960	10,1264	12,7155
6.	197,2710	9,6796	12,5729
7.	217,3730	23,5250	26,8198
8.	197,2450	10,1512	12,6728
9.	202,4240	9,8813	12,8561
10.	198,0520	10,0214	13,3514

regex	Avg (ms)	Overhead (ms)	Per Iteration Avg (ms)	Per Iteration Overhead (ms)
std::regex	200,4203	$${\color{green}{\text{-186,0510}}}$$	0,0200	$${\color{green}{\text{-0,0186}}}$$
PCRE2	11,3248	$${\color{red}{\text{3,0445}}}$$	0,0011	$${\color{red}{\text{0,0003}}}$$
pcre2cpp	14,3694	-	0,0014	-

Installation

To use pcre2cpp, simply download the latest release. There are no additional dependencies required.

1. Download the latest release of pcre2cpp.
2. Link the pcre2cpp library statically in your build system (e.g., CMake or Make).

Example for linking in CMake:

find_package(pcre2cpp REQUIRED)
target_link_libraries(your_project_name PRIVATE pcre2cpp)

Example Usage

Basic Match

#include <pcre2cpp/pcre2cpp.hpp>
#include <iostream>

using namespace std;
using namespace pcre2cpp;

int main() {
    regex expression("\\d+");
    
    if (expression.match("2")) { // is true
        cout << "Matches" << endl;
    }

    if (expression.match("a")) { // is false
        cout << "Matches" << endl;
    }

    if (expression.match("a2")) { // is true
        cout << "Matches" << endl;
    }
    
    return 0;
}

Match with Result

#include <pcre2cpp/pcre2cpp.hpp>
#include <iostream>

using namespace std;
using namespace pcre2cpp;

int main() {
    regex expression("\\d+");
    
    match_result result;
    if (expression.match("aa2", result, 2)) { // is true
        cout << "Matches result: " << result.get_result_value() << " at: " 
             << to_string(result.get_result_global_offset()) << endl;

        // Should print "Matches result: 2 at: 2"
    }
    
    return 0;
}

Match at Specified Offset

#include <pcre2cpp/pcre2cpp.hpp>
#include <iostream>

using namespace std;
using namespace pcre2cpp;

int main() {
    regex expression("\\d+");
    
    if (expression.match_at("aa2", 3, 2)) { // is true
        cout << "Matches result: 2 at: 2" << endl;
    }

    if (expression.match_at("aa2", 3, 1)) { // is false
        cout << "Matches result: 2 at: 2" << endl;
    }
    
    return 0;
}

Match at Specified Offset with Result

#include <pcre2cpp/pcre2cpp.hpp>
#include <iostream>

using namespace std;
using namespace pcre2cpp;

int main() {
    regex expression("\\d+");
    
    match_result result;
    if (expression.match_at("aa2", 3, result, 2)) { // is true
        cout << "Matches result: " << result.get_result_value() << " at: " 
             << to_string(result.get_result_global_offset()) << endl;

        // Should print: "Matches result: 2 at: 2"
    }
    
    return 0;
}

Match with Indexed Subexpression

#include <pcre2cpp/pcre2cpp.hpp>
#include <iostream>

using namespace std;
using namespace pcre2cpp;

int main() {
    regex expression("(\\d+)(a)");
    
    match_result result;
    if (expression.match("ab23a", result, 1)) { // is true
        cout << "Sub Match 0 result: " << result.get_sub_result_value(0) << " at: "
        << result.get_sub_result_global_offset(0) << ", Sub Match 1 result: "
        << result.get_sub_result_value(1) << " at: " 
        << result.get_sub_result_global_offset(1) << endl;

        // Should print: "Sub Match 0 result: 23 at: 2, Sub Match 1 result: a at: 4"
    }
    
    return 0;
}

Match with Named Subexpression

#include <pcre2cpp/pcre2cpp.hpp>
#include <iostream>

using namespace std;
using namespace pcre2cpp;

int main() {
    regex expression("(?<number>\\d+)(?<a>a)");
    
    match_result result;
    if (expression.match("ab23a", result, 1)) { // is true
        cout << "Sub Match <number> result: " << result.get_sub_result_value("number")
        << " at: " << result.get_sub_result_global_offset("number") 
        << ", Sub Match 1 result: " << result.get_sub_result_value("a") 
        << " at: " << result.get_sub_result_global_offset("a") << endl;

        // Should print: "Sub Match <number> result: 23 at: 2, Sub Match <a> result: a at: 4"
    }
    
    return 0;
}

Match All

#include <pcre2cpp/pcre2cpp.hpp>
#include <iostream>

using namespace std;
using namespace pcre2cpp;

int main() {
    regex expression("\\d+");
    
    std::vector<match_result> results;
    if (expression.match_all("Ala ma 23 lata i 3 koty", 23, results)) { // is true
        cout << "Match 0 result: " << results[0].get_result_value() 
        << " at: " << results[0].get_result_global_offset() 
        << ", Match 1 result: " << results[1].get_result_value() 
        << " at: " << results[1].get_result_global_offset() << endl;

        // Should print: "Match 0 result: 23 at: 7, Match 1 result: 3 at: 17"
    }

    match_result* resultsPtr;
    size_t resultsCount;
    if (expression.match_all("Ala ma 23 lata i 3 koty", 23, resultsPtr, resultsCount)) { // is true
        cout << "Match 0 result: " << resultsPtr[0].get_result_value() 
        << " at: " << resultsPtr[0].get_result_global_offset() 
        << ", Match 1 result: " << resultsPtr[1].get_result_value() 
        << " at: " << resultsPtr[1].get_result_global_offset() << endl;

        // Should print: "Match 0 result: 23 at: 7, Match 1 result: 3 at: 17"

        delete[] resultsPtr;
    }
    
    return 0;
}

Offsets Graph

License

This project is licensed under the BSD 3-Clause License with Attribution Requirement. For more details, check the LICENSE file.

Acknowledgments

This project includes code from the PCRE2 library, distributed under the BSD License.