Usage improvements

include/matioCpp/Struct.h

@@ -215,23 +215,8 @@ class matioCpp::Struct : public matioCpp::Variable
      */
     const matioCpp::Variable operator[](index_type el) const;
 
-    /**
-     * @brief Access field at a specific index.
-     * @param el The name of the field to be accessed.
-     * @return A Variable with a weak ownership to the underlying mat variable. This means that the data can be changed,
-     * but the variable cannot be resized and the name cannot change.
-     * @note If the field is not found, the output variable is not valid.
-     */
-    matioCpp::Variable operator[](const std::string& el);
+    using Variable::operator[];
 
-    /**
-     * @brief Access field at a specific index.
-     * @param el The name of the field to be accessed.
-     * @warning Each element of el has to be strictly smaller than the corresponding dimension.
-     * @return A const Variable with a weak ownership to the underlying mat variable.
-     * @note If the field is not found, the output variable is not valid.
-     */
-    const matioCpp::Variable operator[](const std::string& el) const;
 };
 
 #endif // MATIOCPP_STRUCT_H

include/matioCpp/Variable.h

@@ -127,9 +127,10 @@ class matioCpp::Variable
     /**
      * @brief Get the index of the specified field in the variable, considered as a struct
      * @param field The field to search
-     * @return The index of the field, the output of getStructNumberOfFields() if not found.
+     * @param index The index of the field
+     * @return True if successfull, false otherwise.
      */
-    size_t getStructFieldIndex(const std::string& field) const;
+    bool getStructFieldIndex(const std::string& field, size_t& index) const;
 
     /**
      * @brief Set the field of the struct at the specified position
@@ -328,6 +329,26 @@ class matioCpp::Variable
      */
     bool isValid() const;
 
+    /**
+     * @brief Access field with specific name.
+     * @param el The name of the field to be accessed.
+     * @return A Variable with a weak ownership to the underlying mat variable. This means that the data can be changed,
+     * but the variable cannot be resized and the name cannot change.
+     * @note This works only if the variable is a struct.
+     * @note If the field is not found, the output variable is not valid.
+     */
+    matioCpp::Variable operator[](const std::string& el);
+
+    /**
+     * @brief Access field with specific name.
+     * @param el The name of the field to be accessed.
+     * @warning Each element of el has to be strictly smaller than the corresponding dimension.
+     * @return A const Variable with a weak ownership to the underlying mat variable.
+     * @note This works only if the variable is a struct.
+     * @note If the field is not found, the output variable is not valid.
+     */
+    const matioCpp::Variable operator[](const std::string& el) const;
+
     /**
      * @brief Cast the variable as a Element.
      *

src/File.cpp

@@ -124,6 +124,13 @@ void matioCpp::File::close()
 
 bool matioCpp::File::open(const std::string &name, matioCpp::FileMode mode)
 {
+    struct stat info;
+
+    if (stat(name.c_str(), &info) != 0)
+    {
+        std::cerr << "[ERROR][matioCpp::File::open] The file " << name << " does not exists." << std::endl;
+        return false;
+    }
     int matio_mode = mode == matioCpp::FileMode::ReadOnly ? mat_acc::MAT_ACC_RDONLY : mat_acc::MAT_ACC_RDWR;
     m_pimpl->reset(Mat_Open(name.c_str(), matio_mode), mode);
     return isOpen();

src/Struct.cpp

@@ -162,12 +162,15 @@ void matioCpp::Struct::clear()
 
 bool matioCpp::Struct::isFieldExisting(const std::string &field) const
 {
-    return getStructFieldIndex(field) < numberOfFields();
+    size_t index;
+    return getStructFieldIndex(field, index);
 }
 
 size_t matioCpp::Struct::getFieldIndex(const std::string &field) const
 {
-    return getStructFieldIndex(field);
+    size_t index;
+    getStructFieldIndex(field, index);
+    return index;
 }
 
 bool matioCpp::Struct::setField(matioCpp::Struct::index_type index, const matioCpp::Variable &newValue)
@@ -223,19 +226,3 @@ const matioCpp::Variable matioCpp::Struct::operator[](matioCpp::Struct::index_ty
     assert(el < numberOfFields() && "The specified index is out of bounds");
     return getStructField(el);
 }
-
-matioCpp::Variable matioCpp::Struct::operator[](const std::string &el)
-{
-    size_t index = getFieldIndex(el);
-    assert(index < numberOfFields() && "The specified field does not exist.");
-    return getStructField(index);
-}
-
-const matioCpp::Variable matioCpp::Struct::operator[](const std::string &el) const
-{
-    size_t index = getFieldIndex(el);
-    assert(index < numberOfFields() && "The specified field does not exist.");
-    return getStructField(index);
-}
-
-

src/StructArray.cpp

@@ -371,12 +371,15 @@ void matioCpp::StructArray::clear()
 
 bool matioCpp::StructArray::isFieldExisting(const std::string &field) const
 {
-    return getStructFieldIndex(field) < numberOfFields();
+    size_t index;
+    return getStructFieldIndex(field, index);
 }
 
 size_t matioCpp::StructArray::getFieldIndex(const std::string &field) const
 {
-    return getStructFieldIndex(field);
+    size_t index;
+    getStructFieldIndex(field, index);
+    return index;
 }
 
 bool matioCpp::StructArray::addField(const std::string &newField)

src/Variable.cpp

@@ -232,23 +232,26 @@ char * const * matioCpp::Variable::getStructFields() const
     return Mat_VarGetStructFieldnames(m_handler->get());
 }
 
-size_t matioCpp::Variable::getStructFieldIndex(const std::string &field) const
+bool matioCpp::Variable::getStructFieldIndex(const std::string& field, size_t& index) const
 {
     size_t i = 0;
     size_t numberOfFields = getStructNumberOfFields();
     char * const * fields = getStructFields();
+    index = numberOfFields;
 
     if (!fields)
     {
-        return numberOfFields;
+        return false;
     }
 
     while (i < numberOfFields && (strcmp(fields[i], field.c_str()) != 0))
     {
         ++i;
     }
 
-    return i;
+    index = i;
+
+    return index < numberOfFields;
 }
 
 bool matioCpp::Variable::setStructField(size_t index, const matioCpp::Variable &newValue, size_t structPositionInArray)
@@ -312,13 +315,14 @@ bool matioCpp::Variable::setStructField(const std::string& field, const matioCpp
         return false;
     }
 
-    size_t fieldindex = getStructFieldIndex(field);
+    size_t fieldindex;
 
-    if ((fieldindex == getStructNumberOfFields()) && !((getArrayNumberOfElements() == 1) && addStructField(field)))
+    if (!getStructFieldIndex(field, fieldindex) && !((getArrayNumberOfElements() == 1) && addStructField(field)))
     {
         //This is the case when the field has not been found and, either there are more than one elements (i.e. it is part of an array), or there was an error in adding the field
         return false;
     }
+    //If it was not found, but the field has been added, the fieldindex is the last one
 
     return setStructField(fieldindex, newValue, structPositionInArray);
 }
@@ -544,6 +548,42 @@ bool matioCpp::Variable::isValid() const
     return m_handler->get() && checkCompatibility(m_handler->get(), m_handler->variableType(), m_handler->valueType());
 }
 
+matioCpp::Variable matioCpp::Variable::operator[](const std::string& el)
+{
+    if (variableType() != matioCpp::VariableType::Struct)
+    {
+        std::cerr << "[ERROR][matioCpp::Variable::operator[]] The operator[](string) can be used only with structs." << std::endl;
+        assert(false);
+        return matioCpp::Variable();
+    }
+    size_t index;
+    if (!getStructFieldIndex(el, index))
+    {
+        std::cerr << "[ERROR][matioCpp::Variable::operator[]] The field " << el << " does not exist." << std::endl;
+        assert(false);
+        return matioCpp::Variable();
+    }
+    return getStructField(index);
+}
+
+const matioCpp::Variable matioCpp::Variable::operator[](const std::string& el) const
+{
+    if (variableType() != matioCpp::VariableType::Struct)
+    {
+        std::cerr << "[ERROR][matioCpp::Variable::operator[]] The operator[](string) can be used only with structs." << std::endl;
+        assert(false);
+        return matioCpp::Variable();
+    }
+    size_t index;
+    if (!getStructFieldIndex(el, index))
+    {
+        std::cerr << "[ERROR][matioCpp::Variable::operator[]] The field " << el << " does not exist." << std::endl;
+        assert(false);
+        return matioCpp::Variable();
+    }
+    return getStructField(index);
+}
+
 matioCpp::CellArray matioCpp::Variable::asCellArray()
 {
     return matioCpp::CellArray(*m_handler);

test/FileUnitTest.cpp

@@ -561,3 +561,9 @@ TEST_CASE("Write version 4")
     REQUIRE(boolVector(2));
     REQUIRE_FALSE(boolVector(3));
 }
+
+TEST_CASE("Open not existing file")
+{
+    matioCpp::File file;
+    REQUIRE_FALSE(file.open("notExisting.mat"));
+}

test/StructArrayUnitTest.cpp

@@ -357,6 +357,8 @@ TEST_CASE("Assignments and modifications")
             size_t numberOfFields = in.numberOfFields();
             REQUIRE(numberOfFields == arrayFields.size());
 
+            REQUIRE(in.getFieldIndex("notExisting") == numberOfFields);
+
             in.addField("addedField");
 
             REQUIRE(in.numberOfFields() == numberOfFields + 1);

test/VariableUnitTest.cpp

@@ -357,5 +357,26 @@ TEST_CASE("Conversions")
     }
 }
 
+TEST_CASE("operator[](string)")
+{
+    std::vector<size_t> dimensions = {1, 1};
+    std::vector<matvar_t*> pointers;
+    pointers.emplace_back(Mat_VarDuplicate(matioCpp::Vector<double>("vector").toMatio(), 1));
+    pointers.emplace_back(Mat_VarDuplicate(matioCpp::Element<int>("element").toMatio(), 1));
+    pointers.emplace_back(Mat_VarDuplicate(matioCpp::MultiDimensionalArray<double>("array").toMatio(), 1));
+    pointers.emplace_back(Mat_VarDuplicate(matioCpp::String("name", "content").toMatio(), 1));
+    pointers.emplace_back(Mat_VarDuplicate(matioCpp::Struct("otherStruct", { matioCpp::String("name", "anotherContent") }).toMatio(), 1));
+    pointers.emplace_back(nullptr);
+
+    matvar_t* matioVar = Mat_VarCreate("test", matio_classes::MAT_C_STRUCT, matio_types::MAT_T_STRUCT, 2, dimensions.data(), pointers.data(), 0);
+    REQUIRE(matioVar);
+
+    matioCpp::Variable sharedVar((matioCpp::SharedMatvar(matioVar)));
 
+    REQUIRE(sharedVar["name"].asString()() == "content");
 
+    const matioCpp::Variable& constRef = sharedVar;
+    REQUIRE(constRef["name"].asString()() == "content");
+
+    REQUIRE(sharedVar["otherStruct"]["name"].asString()() == "anotherContent");
+}