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Json::Value constructor: Accept any arithmetic type. #66

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Json::Value constructor: Accept any arithmetic type. #66

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e384e49
Merge pull request #63 from dreifachstein/master
cdunn2001 Nov 5, 2014
021f7de
Json::Value constructor: Accept any arithmetic type.
Nov 7, 2014
7ba2c54
Improve comments on arithmetic type constructor and helper traits.
Nov 8, 2014
1787b6d
Make 64-bit int work with 'long int' and 'int64_t' for 64 bit builds …
orodbhen Nov 7, 2014
7e29d49
Only use fix-width types for C++11 (Issue #64)
orodbhen Nov 9, 2014
337b0d2
Json::Value constructor: Accept any arithmetic type.
Nov 7, 2014
e555666
Improve comments on arithmetic type constructor and helper traits.
Nov 8, 2014
5512aaa
Merge branch 'accept_all_arithmetic_types' of https://github.com/open…
Nov 10, 2014
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52 changes: 45 additions & 7 deletions include/json/value.h
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Original file line number Diff line number Diff line change
Expand Up @@ -9,6 +9,7 @@
#if !defined(JSON_IS_AMALGAMATION)
#include "forwards.h"
#endif // if !defined(JSON_IS_AMALGAMATION)
#include <limits>
#include <string>
#include <vector>

Expand Down Expand Up @@ -84,6 +85,30 @@ class JSON_API StaticString {
const char* str_;
};

// Some helper traits for Json::Value
namespace Detail {

template <typename T>
struct IsIntegral {
enum { value = std::numeric_limits<T>::is_specialized &&
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Mostly out of curiosity: why this is_specialized here? According to cppreference, is_integer is false for non-specialized types. Maybe that's not guaranteed for future versions of the standard?

std::numeric_limits<T>::is_integer };
};

template <typename T>
struct IsFloatingPoint {
enum { value = std::numeric_limits<T>::is_specialized &&
!std::numeric_limits<T>::is_integer };
};

template <bool C, typename T = void> struct EnableIf { };
template <typename T> struct EnableIf<true, T> { typedef T type; };

template <typename T>
struct EnableIfArithmetic
: EnableIf<IsIntegral<T>::value || IsFloatingPoint<T>::value, int> {};

} // namespace Detail

/** \brief Represents a <a HREF="http://www.json.org">JSON</a> value.
*
* This class is a discriminated union wrapper that can represents a:
Expand Down Expand Up @@ -210,13 +235,26 @@ Json::Value obj_value(Json::objectValue); // {}
\endcode
*/
Value(ValueType type = nullValue);
Value(Int value);
Value(UInt value);
#if defined(JSON_HAS_INT64)
Value(Int64 value);
Value(UInt64 value);
#endif // if defined(JSON_HAS_INT64)
Value(double value);

template <typename T>
Value(T value, typename Detail::EnableIfArithmetic<T>::type = 0)
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Comment explaining what is going on here, maybe with the key word 'SFINAE' for those unfamiliar.

: allocated_(false),
#ifdef JSON_VALUE_USE_INTERNAL_MAP
itemIsUsed_(0),
#endif
comments_(0), start_(0), limit_(0) {
if (Detail::IsFloatingPoint<T>::value) {
type_ = realValue;
value_.real_ = value;
} else if (std::numeric_limits<T>::is_signed) {
type_ = intValue;
value_.int_ = value;
} else {
type_ = uintValue;
value_.uint_ = value;
}
}

Value(const char* value);
Value(const char* beginValue, const char* endValue);
/** \brief Constructs a value from a static string.
Expand Down
57 changes: 0 additions & 57 deletions src/lib_json/json_value.cpp
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Original file line number Diff line number Diff line change
Expand Up @@ -267,63 +267,6 @@ Value::Value(ValueType type)
}
}

Value::Value(UInt value)
: type_(uintValue), allocated_(false)
#ifdef JSON_VALUE_USE_INTERNAL_MAP
,
itemIsUsed_(0)
#endif
,
comments_(0), start_(0), limit_(0) {
value_.uint_ = value;
}

Value::Value(Int value)
: type_(intValue), allocated_(false)
#ifdef JSON_VALUE_USE_INTERNAL_MAP
,
itemIsUsed_(0)
#endif
,
comments_(0), start_(0), limit_(0) {
value_.int_ = value;
}

#if defined(JSON_HAS_INT64)
Value::Value(Int64 value)
: type_(intValue), allocated_(false)
#ifdef JSON_VALUE_USE_INTERNAL_MAP
,
itemIsUsed_(0)
#endif
,
comments_(0), start_(0), limit_(0) {
value_.int_ = value;
}

Value::Value(UInt64 value)
: type_(uintValue), allocated_(false)
#ifdef JSON_VALUE_USE_INTERNAL_MAP
,
itemIsUsed_(0)
#endif
,
comments_(0), start_(0), limit_(0) {
value_.uint_ = value;
}
#endif // defined(JSON_HAS_INT64)

Value::Value(double value)
: type_(realValue), allocated_(false)
#ifdef JSON_VALUE_USE_INTERNAL_MAP
,
itemIsUsed_(0)
#endif
,
comments_(0), start_(0), limit_(0) {
value_.real_ = value;
}

Value::Value(const char* value)
: type_(stringValue), allocated_(true)
#ifdef JSON_VALUE_USE_INTERNAL_MAP
Expand Down
37 changes: 37 additions & 0 deletions src/test_lib_json/main.cpp
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Original file line number Diff line number Diff line change
Expand Up @@ -6,6 +6,7 @@
#include "jsontest.h"
#include <json/config.h>
#include <json/json.h>
#include <climits>
#include <stdexcept>

// Make numeric limits more convenient to talk about.
Expand Down Expand Up @@ -394,6 +395,42 @@ JSONTEST_FIXTURE(ValueTest, integers) {

JSONTEST_ASSERT_EQUAL(Json::uintValue, val.type());

// A few more integral types
// special
JSONTEST_ASSERT_EQUAL(Json::booleanValue,
Json::Value(static_cast<bool>(0)).type());
JSONTEST_ASSERT_EQUAL(Json::uintValue,
Json::Value(static_cast<std::size_t>(0)).type());
JSONTEST_ASSERT_EQUAL(Json::intValue,
Json::Value(static_cast<std::ptrdiff_t>(0)).type());
// signed
JSONTEST_ASSERT_EQUAL(Json::intValue,
Json::Value(static_cast<signed char>(0)).type());
JSONTEST_ASSERT_EQUAL(Json::intValue,
Json::Value(static_cast<short>(0)).type());
JSONTEST_ASSERT_EQUAL(Json::intValue,
Json::Value(static_cast<int>(0)).type());
JSONTEST_ASSERT_EQUAL(Json::intValue,
Json::Value(static_cast<long>(0)).type());
// unsigned
JSONTEST_ASSERT_EQUAL(Json::uintValue,
Json::Value(static_cast<unsigned char>(0)).type());
JSONTEST_ASSERT_EQUAL(Json::uintValue,
Json::Value(static_cast<unsigned short>(0)).type());
JSONTEST_ASSERT_EQUAL(Json::uintValue,
Json::Value(static_cast<unsigned>(0)).type());
JSONTEST_ASSERT_EQUAL(Json::uintValue,
Json::Value(static_cast<unsigned long>(0)).type());
// long long types if available
#ifdef LLONG_MAX
JSONTEST_ASSERT_EQUAL(Json::intValue,
Json::Value(static_cast<long long>(0)).type());
#endif
#ifdef ULLONG_MAX
JSONTEST_ASSERT_EQUAL(Json::uintValue,
Json::Value(static_cast<unsigned long long>(0)).type());
#endif

checks = IsCheck();
checks.isInt_ = true;
checks.isInt64_ = true;
Expand Down